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Pierce™ Lys-C Protease, MS-grade Thermo Scientific™

Thermo Scientific™ Pierce™ Lys-C Protease, MS Grade is a highly purified native endoproteinase validated for maximum activity and stability in proteomic applications.

Features of Lys-C Protease, MS Grade include:
Enhanced digestion—use in tandem with trypsin to decrease tryptic missed cleavages
Increased sequence coverage—better protein characterization results from overlapping peptides with complementary chromatographic, ionization, and fragmentation properties
Versatility—effective enzyme activity under highly denaturing conditions (e.g., 8 M urea)
C-terminal lysine cleavage specificity—at least 90% for a complex protein sample
Stability—provided in a lyophilized format

Product details
This is a mass spectrometry (MS)-grade serine protease isolated from Lysobacter enzymogenes. Lys-C protease has high activity and specificity for lysine residues, resulting in larger peptides and less sample complexity than trypsin (i.e., fewer peptides). Unlike trypsin, Lys-C protease can cleave lysines followed by prolines, making it ideal for sequential protein digestion followed by trypsin to decrease missed cleavages. These unique Lys-C protease properties ensure high digestion efficiency when used alone or followed by tryptic digestion. Additionally, Lys-C prototypic peptides typically have higher charge states, making it an enzyme of choice for use with ETD fragmentation.

Lys-C protease is commonly used in phosphopeptide enrichment workflows because it generates peptides with primary amines at both the N- and C-terminus, allowing the fragments to be double-labeled with amine-reactive isobaric tags. This results in enhanced peptide ionization and improved limits of quantitation since more fragment ions can be re-isolated during MS3 acquisition. This enzyme can be used for in-solution or in-gel digestion workflows to produce peptides for LC-MS/MS protein identification. This Lys-C enzyme is packaged lyophilized (20 µg or 100 µg quantities).

The endoproteinase Lys-C specifically hydrolyzes proteins at the carboxyl side of lysine. Efficient protein digestion can be completed in 2 hours at 37°C. Lys-C protease remains active in highly denaturing conditions such as 8 M urea, 2 M guanidine-HCl, 1% SDS, 2% CHAPS, and 40% acetonitrile and functions well within pH 7–9 (maximal activity at pH 8). This lyophilized enzyme has a mass of 30 kDa and is stable for 1 year when stored at –20°C.

Applications
• Improved sequence coverage of protein digests
• De novo sequencing
• Epigenetic studies
• In-gel and in-solution digestion of proteins

TMT10plex™ Isobaric Label Reagent Set, 8 x 0.2 mg Thermo Scientific™

Amine-reactive Thermo Scientific TMT10plex™ Isobaric Mass Tag Labeling Reagents Sets enable multiplexed protein identification and quantitative analysis by tandem mass spectrometry (MS).

This Tandem Mass Tag™ (TMT™) 10-plex reagent set contains ten different isobaric compounds with the same mass and chemical structure (i.e., isotopomeric) composed of an amine-reactive NHS-ester group, a spacer arm and a mass reporter. The reagent set enables up to ten different peptide samples prepared from cells or tissues to be labeled in parallel and then combined for analysis. For each sample, a unique reporter mass (i.e., TMT10 126-131Da) in the low-mass region of the high-resolution MS/MS spectrum is used to measure relative protein expression levels during peptide fragmentation and tandem mass spectrometry.

Features of this TMT10plex Isobaric Label Reagent Set:

Powerful – concurrent MS analysis of multiple samples increases sample throughput and enables relative quantitation of up to ten different samples derived from cells, tissues or biological fluids
Consistent – identical reagent structure and performance among TMTzero™, TMTduplex™, TMTsixplex™ and TMT10plex™ reagents allows efficient transition from method development to multiplex quantitation, enabling biomarker discovery research across platforms and datasets
Robust – increased multiplex capability results in fewer missing quantitative values among samples and higher confidence among replicates
Efficient – amine-reactive, NHS-ester-activated reagents ensure efficient labeling of all peptides regardless of protein sequence or proteolytic enzyme specificity
Compatible – optimized for use with high resolution Thermo Scientific MS/MS platforms, such as the Q Exactive, Orbitrap Elite™ and Orbitrap Fusion™ Tribrid™ instruments with data analysis fully supported by Proteome Discoverer™ 1.4

Applications:
• Protein identification and quantitation from multiple samples of cells, tissue or biological fluids
• Protein expression profiling of normal vs. disease states or control vs. treated
• Multiplex up to ten different samples concurrently in a single experiment
• Quantitative analysis of proteins for which no antibodies are available
• Identification and quantitation of membrane and post-translationally modified proteins
• Identification and quantification of hundreds to thousands of proteins in a single experiment

The Tandem Mass Tag (TMT) Reagents are specially designed to enable identification and quantitation of proteins in different samples using tandem mass spectrometry. The TMT10plex Label Reagents share an identical structure with TMTzero, TMTduplex, and TMTsixplex Reagents but contain different numbers and combinations of 13C and 15N isotopes in the mass reporter. The different isotopes result in a 10-plex set of tags that have mass differences in the reporter that can be detected using high resolution Orbitrap MS instruments.

Advantages of the TMT10plex Label Reagents include increased multiplex relative quantitation, increased sample throughput, and fewer missing quantitative values among samples. TMT10plex Label Reagents are ideal for analysis of multiple protein samples from inhibitor dose response experiments, time course experiments or biological replicates.

TMT Reagents are provided as standalone sets or in optimized kit formats containing all necessary reagents and controls for maximum flexibility, convenience and reliability. When combined with the industry-leading, high resolution Thermo Scientific Orbitrap instruments and software, TMT10plex Reagents provide integrated total solutions for quantitative protein expression analysis.

These products are subject to a limited use label license.

Related Products
TMT10plex™ Isobaric Mass Tag Labeling Kit
1M Triethylammonium bicarbonate (TEAB) for TMT experiments
50% Hydroxylamine for TMT experiments

In-Solution Tryptic Digestion and Guanidination Kit Thermo Scientific™

The Thermo Scientific Pierce In-Solution Tryptic Digestion and Guanidination Kit contains proteomics-grade trypsin, buffers and reagents to alkylate and digest proteins and then guanidinate the peptide fragments for mass spectrometry.

Features of the kit:

Optimized trypsin digestion—produce complete digests of protein ranging from 0.025 to 10 µg
Optimized guanidination—reaction produces little to no N-terminal modification
Convenient—kit includes reagents for digestion, reduction, alkylation and guanidination.
Quick—protein can be digested and guanidinated all in one day

Accurate identification of proteins and analysis of post-translational modifications by mass spectrometry require accurate and complete protein digestion and peptide modification. The In-Solution Tryptic Digestion and Guanidination kit provides an optimized procedure and reagents for approximately 90 digests, each containing 0.025 to 10 µg of protein.

Trypsin specifically cleaves peptide bonds at the carboxyl side of arginine and lysine residues. The signals from the arginine-containing peptides are generally stronger, due to the more basic side chain. To enhance overall ionization, guanidination is necessary to convert lysines to homoarginines. The guanidination reaction is specific for the amine of lysine but may occur minimally at the amine of the peptide's N-terminus. This derivatization leads to an increase in the intensity of the lysine containing peptides and improved sequence coverage overall.

Immobilized Pepsin (Agarose Resin) Thermo Scientific™

Thermo Scientific Pierce Immobilized Pepsin Agarose consists of an acidic endopeptidase (pepsin) that has been immobilized onto beaded agarose resin to enable generation and purification of Fab and F(ab')2 fragments from antibodies.

Pepsin is a nonspecific acidic endopeptidase produced in an inactive precursor form (pepsinogen) in the mucosal lining of the stomach of vertebrates. There are several pepsins, each with a molecular weight of 35,000 and an optimum pH of 1-3; at pH >6, the enzyme is permanently inactivated. Pepsin has broad substrate specificity. It cleaves proteins preferentially at carboxylic groups of aromatic amino acids such as phenylalanine, tryptophan and tyrosine. It will not cleave at bonds containing valine, alanine or glycine. Cleavage at other residues occurs with varying efficiency.

Pepsin and other proteolytic enzymes are used in the laboratory analysis of various proteins. Pepsin and papain are often used to generate antibody fragments. Papain is used to cleave antibodies into Fab fragments, which contain a single antigen-binding domain. Pepsin is used to generate F(ab')2 fragments by removing only that portion of the Fc domain beyond the hinge region. The resulting F(ab')2 fragments are composed of two antibody-binding Fab' fragments connected by disulfides in the hinge region.

Immobilized pepsin can be substituted for free pepsin in any application, and is advantageous because it virtually eliminates autolysis, eliminates contamination of a sample with the protease and allows control of the digestion by removing the pepsin. Immobilized pepsin is also more stable against heat-induced denaturation, resulting in longer maintenance of activity. The F(ab')2 Preparation Kit contains immobilized pepsin, other necessary reagents and an optimized protocol for human, rabbit and mouse antibody digestion.

Texas Red™-X, Succinimidyl Ester, single isomer Invitrogen™

The amine-reactive Texas Red®-X, succinimidyl ester can be used to can be used to create bright red-fluorescent bioconjugates with excitation/emission maxima ~595/615 nm. This reactive dye contains an additional seven-atom aminohexanoyl spacer ('X') between the fluorophore and the succinimidyl ester group. This spacer helps to separate the fluorophore from its point of attachment, potentially reducing the interaction of the fluorophore with the biomolecule to which it is conjugated.

Pierce™ 2-Mercaptoethanol Thermo Scientific™

Thermo Scientific Pierce 2-Mercaptoethanol (2-ME), also called beta-mercaptoethanol (b-ME), is a mild reducing agent for cleaving protein disulfide bonds.

Features of 2-mercaptoethanol:

• Also known as β-mercaptoethanol, beta-mercaptoethanol, bME, b-ME
• Mild but effective reducing agent, often included in enzyme solutions to protect against catalytic site inactivation due to cysteine sulfhydryl oxidation/disulfide formation; added at final concentrations of 5 and 20 mM, with or without EDTA, as an additional protectant

Related Products
Pierce™ TCEP-HCl
Pierce™ DTT (Dithiothreitol)

NeuCode™ Lysine-080 Thermo Scientific™

Thermo Scientific™ NeuCode™ amino acids augment the level of multiplexing achievable for the metabolic labeling of proteins for mass spectrometry analysis. NeuCode™ Lysine-080 (3,3,4,4,5,5,6,6-D8 L-Lysine-2HCl) may also be used with traditional SILAC to improve flexibility of multiplexing options or to reduce complexity of analysis.

General features of NeuCode SILAC labeling:
• Labeling efficiency—100% label incorporation into proteins of living cells without toxicity
• Compatible—may be multiplexed with existing SILAC amino acids
• Time-saving—not necessary to label to 100% incorporation if only using heavy amino acids
• High-quality supplements—heavy amino acids with >98% isotope purity

Stable isotope labeling with amino acids in cell culture (SILAC) is a powerful method to identify and quantify relative differential changes in complex protein samples. NeuCode metabolic labeling is similar to SILAC, but differs in that the labeling only utilizes heavy amino acids. The increased multiplexing capability of NeuCode amino acids is possible through the use of mass defects from extra neutrons in the stable isotopes. These small mass differences may be resolved on high resolution mass spectrometers (Thermo Scientific™ Orbitrap™ Elite™, Q Exactive™, Orbitrap™ Fusion™ Tribrid™, and Orbitrap™ Fusion™ Lumos™ Tribrid™ mass spectrometers). Use of only heavy amino acids eliminates the need for 100% incorporation of amino acids used for SILAC (both heavy and light), and may be especially useful for studies with primary cells.

NeuCode amino acids are used together with specialized cell culture media that are deficient in essential amino acids. Heavy L-lysine is used for SILAC analysis of peptides that have been digested with trypsin or LysC. NeuCode Lysine-080 may be used with 4,4,5,5-D4 L-lysine or 13C6 15N2 L-lysine for duplex experiments and may be combined with light lysine for three-plex experiments.

Related products
L-Lysine-2HCl, 4,4,5,5-D4 for SILAC
L-Lysine-2HCl, 13C6, 15N2 for SILAC
Fetal Bovine Serum, dialyzed, US origin
DMEM Media for SILAC

NeuCode is a trademark of WARF.

Pierce™ TCEP-HCl Thermo Scientific™

Thermo Scientific Pierce TCEP-HCl is a potent, versatile, odorless, thiol-free reducing agent with broad application to protein and other research involving reduction of disulfide bonds. The unique compound is easily soluble and very stable in many aqueous solutions. TCEP reduces disulfide bonds as effectively as dithiothreitol (DTT), but unlike DTT and other thiol-containing reducing agents, TCEP does not have to be removed before certain sulfhydryl-reactive crosslinking reactions.

Thermo Scientific No-Weigh products are specialty reagents provided in a pre-aliquoted format. The pre-weighed packaging prevents the loss of reagent reactivity and contamination over time by eliminating the repetitive opening and closing of the vial. The format enables use of a fresh vial of reagent each time, eliminating the hassle of weighing small amounts of reagents and reducing concerns over reagent stability.

Features of TCEP-HCl:

Odorless—Unlike DTT or BME, TCEP is odor-free, so it can reduce proteins conveniently on the bench; contributes to a healthier lab environment
Specific—selective and complete reduction of even the most stable water-soluble disulfides over a wide pH range
Simple—effective reduction at room temperature and pH 5 in less than five minutes
Stable—it's inherent stability and resistant to air oxidation eliminates the need for any special precautions while handling or storing; non-volatile and non-reactive toward other functional groups found in proteins
Efficient—For most applications, 5 to 50 mM TCEP provides sufficient molar excess to effectively reduce peptide or protein disulfide bonds within a few minutes at room temperature.
Compatible—With TCEP, removal of the reducing agent is not necessary prior to most applications, (e.g. histidine-tagged protein purification, maleimide conjugations).

Considerations for use of TCEP:
• TCEP is generally very soluble in aqueous buffers at nearly any pH. Therefore, working concentrations and 10X stock solutions may be readily prepared in most aqueous buffers.
• TCEP is stable in aqueous, acidic, and basic solutions. When TCEP is dissolved directly in water, the resulting pH is approximately 2.5.
• TCEP is not particularly stable in phosphate buffers, especially at neutral or alkaline pH. Therefore, if TCEP is to be used in PBS buffers, prepare the working solution immediately before use.
• TCEP may be used as a substitute for DTT or 2-mercaptoethanol (2-ME) in sample loading buffer for SDS-PAGE; use a final concentration of 50 mM TCEP.
• Because TCEP is charged in solution, it is not compatible for use in isoelectric focusing.

Trypsin, TPCK Treated Thermo Scientific™

Thermo Scientific Pierce TPCK Trypsin is a serine endoprotease that is applicable to amino acid analysis and protein sequencing, mapping and structural studies; the immobilized form allows sample separation after treatment.

Features of Thermo Scientific Pierce TPCK Trypsin

• Cleaves at carboxyl side of arginine and lysine residues
• Digestion conditions: pH 7.5-9.0, 37°

Trypsin has a wide range of applications including amino acid analysis and protein sequencing, mapping and structural studies. Enzymes such as trypsin and chymotrypsin have become important tools in sequencing studies since they are highly selective in their cleavage of peptide bonds. Trypsin cleaves only those peptide bonds in which the carboxyl group is contributed by a lysine or an arginine residue, regardless of the length or amino acid sequence of the chain. Our Immobilized TPCK Trypsin can be substituted for free trypsin in many application and is advantageous because it minimizes autolysis, eliminates contamination of a sample with the protease and allows control of the digestion by removing the trypsin. Immobilized trypsin is also more stable against heat-induced denaturation, resulting in longer maintenance of activity.

Applications:
• Removal of adherent cells from tissue culture flasks
• Preparing tryptic fragments for Edman degradation sequencing
• Immobilized trypsin can be used to purify soybean trypsin inhibitor
• Use our Pierce Trypsin, MS Grade (Part No. 90057) for mass spectrometry workflows

Trypsin is a 23.8kDa pancreatic serine endoprotease derived from trypsinogen, an inactive precursor zymogen, after enzymatic removal of an n-terminal leader sequence by enterokinase. Once some trypsin has been formed it can catalyze the conversion of more trypsinogen into its catalytically-active form. Trypsin is treated with L-1-tosylamido-2-phenylethyl chloromethyl ketone (TPCK) to inhibit contaminating chymotrypsin activity without affecting trypsin activity.

Related Products
Immobilized Trypsin, TPCK Treated (Agarose Resin)

Pierce™ Iodoacetic Acid Thermo Scientific™

Thermo Scientific Pierce Iodoacetic Acid (IAA) can react with several protein functional groups but is typically used for specific S-carboxymethylation of sulfhydryls (reduced cysteines).

Features of Pierce Iodocetic Acid (IAA):

• React at slightly alkaline pH for specific S-carboxymethylation of free sulfhydryls
• React at low pH for specific carboxymethylation of methionines
• React at high pH to favor carboxymethylation of histidines and lysines
• Methylate reduced cysteine peptide fragments in protease digests for mass spectrometry

Iodoacetic acid reacts with sulfhydryls on cysteines, imidazolyl side chain nitrogens of histidines, the thioether of methionine and the primary amine group of lysines.The rate of reaction and specificity is dependent on the ionization level, which can be manipulated by the pH of the reaction condition.

Related Products
Pierce™ Iodoacetamide, Single-Use

MS(PEG)4 Methyl-PEG-NHS-Ester Reagent Thermo Scientific™

Thermo Scientific Pierce MS(PEG)n reagents are methyl-terminated, polyethylene glycol compounds (n equals 4 to 24 PEG units) activated as NHS esters for covalent pegylation of primary amines on proteins (e.g., lysines) or assay surfaces.

Features of MS(PEG)4:

• NHS-activated for efficient PEGylation of primary amines at pH 7-9; reaction of NHS-ester group results in formation of stable, irreversible amide bonds
• Fully characterized PEGylation reagents with defined PEG chain lengths; molecules of discrete molecular weight for consistency of performance in protein-modification applications
• Provided as a series of 4, 8, 12 and 24 ethylene glycol units, enabling modification procedures to be optimized for a specific application while retaining all the benefits associated with protein PEGylation
• PEG spacer provides unique advantages, including increased stability, reduced tendency toward aggregation and reduced immunogenicity
• Easy-to-follow instructions increase the likelihood of a successful outcome

MS(PEG)n is the abbreviation for a set of compounds having polyethylene glycol (PEG) spacers with methyl (—CH3) and amine-reactive NHS-ester groups at opposite ends. The unbranched, hydrophilic, discrete-length molecules have the form Methyl-PEGn-NHS Ester, where the subscript 'n' denotes 4, 8, 12, or 24 ethylene glycol units. The N-hydroxysuccinimide (NHS) ester is spontaneously reactive with primary amines (—NH2), providing for efficient PEGylation of proteins, peptides and other amine-containing molecules or surfaces.

PEGylation Applications:
• PEGylate amine surfaces
• Add inert mass to proteins, immunogens, drug compounds and probes
• Improve solubility (decrease aggregation) of proteins or peptides without affecting function
• Protect proteins from proteolysis

Why PEGylate a protein or peptide?
PEG-containing reagents have been used to modify proteins to provide specific advantages. Protein PEGylation can improve the stability of the modified protein, protect it from proteolytic digestion, increase its half life in biological applications, mask it from causing an immunogenic response, decrease its antigenicity or potential toxicity, improve its solubility, diminish the potential for aggregation, and minimize interference for both in vitro and in vivo applications. Polyethylene glycol, also called polyethylene oxide (PEO), has these effects because it is nontoxic, nonimmunogenic, hydrophilic, water soluble and highly flexible.

Advantages of Discrete-length mPEG-NHS Ester Compounds
These reagents are specially synthesized as homogeneous compounds of discrete chain length and defined molecular weight. As such, they enable precise control and optimization of surface protein modification experiments. By contrast, typical preparations of PEG compounds are heterogeneous mixtures composed of multiple chain lengths and a range of molecular weights.

Related Products
MS(PEG)8 Methyl-PEG-NHS-Ester Reagent
MS(PEG)12 Methyl-PEG-NHS-Ester Reagent
MS(PEG)24 Methyl-PEG-NHS-Ester Reagent

MM(PEG)12 Methyl-PEG-Maleimide Reagent Thermo Scientific™

Thermo Scientific Pierce MM(PEG)12 is a methyl-terminated, polyethylene glycol compound (12 PEG units) activated with a maleimide group for covalent pegylation of sulfhydryls on proteins (e.g., cysteines) or assay surfaces.

Features of MM(PEG)12:

• Maleimide-activated for efficient PEGylation of sulfhydryl groups at pH 6.5-7.5; reaction of maleimide group results in formation of stable, irreversible thioether bonds
• Fully characterized PEGylation reagents with defined PEG chain lengths; molecules of discrete molecular weight for consistency of performance in protein-modification applications
• Provided with 12 ethylene glycol units, enabling modification procedures to be optimized for a specific application while retaining all the benefits associated with protein PEGylation
• PEG spacer provides unique advantages, including increased stability, reduced tendency toward aggregation and reduced immunogenicity
• Easy-to-follow instructions increase the likelihood of a successful outcome

PEGylation Applications:
• PEGylate amine surfaces
• Add inert mass to proteins, immunogens, drug compounds and probes
• Improve solubility (decrease aggregation) of proteins or peptides without affecting function
• Protect proteins from proteolysis

Why PEGylate a protein or peptide?
PEG-containing reagents have been used to modify proteins to provide specific advantages. Protein PEGylation can improve the stability of the modified protein, protect it from proteolytic digestion, increase its half life in biological applications, mask it from causing an immunogenic response, decrease its antigenicity or potential toxicity, improve its solubility, diminish the potential for aggregation, and minimize interference for both in vitro and in vivo applications. Polyethylene glycol, also called polyethylene oxide (PEO), has these effects because it is nontoxic, nonimmunogenic, hydrophilic, water soluble and highly flexible.

Advantages of Discrete-length mPEG-NHS Ester Compounds:
These reagents are specially synthesized as homogeneous compounds of discrete chain length and defined molecular weight. As such, they enable precise control and optimization of surface protein modification experiments. By contrast, typical preparations of PEG compounds are heterogeneous mixtures composed of multiple chain lengths and a range of molecular weights.

Related Products
MM(PEG)24 Methyl-PEG-Maleimide Reagent

MS(PEG)8 Methyl-PEG-NHS-Ester Reagent Thermo Scientific™

Thermo Scientific Pierce MS(PEG)n reagents are methyl-terminated, polyethylene glycol compounds (n equals 4 to 24 PEG units) activated as NHS esters for covalent pegylation of primary amines on proteins (e.g., lysines) or assay surfaces.

Features of MS(PEG)8:

• NHS-activated for efficient PEGylation of primary amines at pH 7-9; reaction of NHS-ester group results in formation of stable, irreversible amide bonds
• Fully characterized PEGylation reagents with defined PEG chain lengths; molecules of discrete molecular weight for consistency of performance in protein-modification applications
• Provided as a series of 4, 8, 12 and 24 ethylene glycol units, enabling modification procedures to be optimized for a specific application while retaining all the benefits associated with protein PEGylation
• PEG spacer provides unique advantages, including increased stability, reduced tendency toward aggregation and reduced immunogenicity
• Easy-to-follow instructions increase the likelihood of a successful outcome

MS(PEG)n is the abbreviation for a set of compounds having polyethylene glycol (PEG) spacers with methyl (—CH3) and amine-reactive NHS-ester groups at opposite ends. The unbranched, hydrophilic, discrete-length molecules have the form Methyl-PEGn-NHS Ester, where the subscript 'n' denotes 4, 8, 12, or 24 ethylene glycol units. The N-hydroxysuccinimide (NHS) ester is spontaneously reactive with primary amines (—NH2), providing for efficient PEGylation of proteins, peptides and other amine-containing molecules or surfaces.

PEGylation Applications:
• PEGylate amine surfaces
• Add inert mass to proteins, immunogens, drug compounds and probes
• Improve solubility (decrease aggregation) of proteins or peptides without affecting function
• Protect proteins from proteolysis

Why PEGylate a protein or peptide?
PEG-containing reagents have been used to modify proteins to provide specific advantages. Protein PEGylation can improve the stability of the modified protein, protect it from proteolytic digestion, increase its half life in biological applications, mask it from causing an immunogenic response, decrease its antigenicity or potential toxicity, improve its solubility, diminish the potential for aggregation, and minimize interference for both in vitro and in vivo applications. Polyethylene glycol, also called polyethylene oxide (PEO), has these effects because it is nontoxic, nonimmunogenic, hydrophilic, water soluble and highly flexible.

Advantages of Discrete-length mPEG-NHS Ester Compounds
These reagents are specially synthesized as homogeneous compounds of discrete chain length and defined molecular weight. As such, they enable precise control and optimization of surface protein modification experiments. By contrast, typical preparations of PEG compounds are heterogeneous mixtures composed of multiple chain lengths and a range of molecular weights.

Related Products
MS(PEG)4 Methyl-PEG-NHS-Ester Reagent
MS(PEG)12 Methyl-PEG-NHS-Ester Reagent
MS(PEG)24 Methyl-PEG-NHS-Ester Reagent

Pierce™ Sulfhydryl Addition Kit Thermo Scientific™

The Thermo Scientific Pierce Sulfhydryl Addition Kit contains all necessary components to introduce free sulfhydryl groups into any primary amine-containing molecule, purify the modified molecule and quantify the added sulfhydryl groups. SATA is a short-chain (2.8 angstrom spacer arm) reagent for covalent modification of primary amines and addition of a protected yet exposable sulfhydryl group, enabling heterobifunctional crosslinking strategies.

Features of SATA:

• Adds a protected sulfhydryl that can be deprotected by hydroxylamine
• Allows long-term storage of the sulfhydryl-modified molecule
• Forms cleavable disulfide bonds with other sulfhydryl-containing molecules
• Reacts with primary amines (e.g., lysine residues proteins) to form stable amide bonds
• Preserves protein activity with its mild, non-denaturing reaction conditions

SATA (N-succinimidyl S-acetylthioacetate) adds sulfhydryl groups to proteins and other amine-containing molecules in a protected form. The modified molecule can be stored indefinitely and treated with hydroxylamine to expose the labile sulfhydryl group when needed for conjugation reactions. SATA contains an N-hydroxysuccinimide (NHS) ester, which forms a stable, covalent amide bond with primary amines (i.e., lysine residues and the amino termini of proteins) and releases NHS as a by-product. De-protection (deacylation) to generate a free sulfhydryl is accomplished using hydroxylamine-HCl.

Sulfhydryl groups present on proteins, peptides and other compounds are important in protein chemistry/modification reactions. Frequently, thiols are unavailable or absent within the molecules of interest. Several reagents and techniques are available for introducing sulfhydryl groups or disulfides into proteins and peptides, including Traut's Reagent, variants of SPDP, and variants of SATA.

Related Products
Pierce™ SATA (N-succinimidyl S-acetylthioacetate)
Pierce™ SATP
Pierce™ SAT(PEG)4

WELQut Protease (5 U/µL) Thermo Scientific™

Thermo Scientific WELQut Protease is highly specific, recombinant serine protease of Staphylococcus aureus. It recognizes and precisely cleaves recombinant proteins containing an engineered recognition sequence† W- E- L- Q↓X (Trp, Glu, Leu, Gln, X can be any amino acid). The protease cleaves outside the recognition sequence without leaving additional amino acids bound to the target protein.

The WELQut Protease is active in a broad temperature (4 to 30°C) and pH (pH 6.5 to 9.0) range and does not require specific buffers.

In addition, this new protease has several procedural advantages - it is ideal for on-column proteolysis reactions and can be easily removed from reaction mixtures using its built-in His-tag.

Highlights

• Cleaves outside WELQ recognition sequence, without leaving additional amino acids bound to the target protein
• Highly specific to cognate recognition site, does not generate non-specific product bands, even after long incubation and using excess of protease
• Easy to remove from the reaction mixture using built-in His-tag
• Ideal for on-column proteolysis reactions

Applications

• Removal of N-terminal fusion tags from recombinant protein preparations.

Footnote

† This cleavage sequence is present in expression vector pLATE52 included into the Thermo Scientific aLICator LIC Cloning and Expression Kit 4 (N-terminal His-tag/WELQut) (#K1281) available from Thermo Scientific.
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