Vous avez recherché : Enzymes

Supplier: MP Biomedicals

Deoxyribonuclease from beef pancreas, DNase I, was first crystallized by Kunitz. It is an endonuclease which splits phosphodiester linkages, preferentially adjacent to a pyrimidine nucleotide yielding 5'-phosphate terminated polynucleotides with a free hydroxyl group on position 3'. The average chain of limit digest is a tetranucleotide. DNase I acts upon single chain DNA, and upon double-stranded DNA and chromatin.

Supplier: Cytiva

Exonuclease I acts specifically on single-stranded DNA degrading it processively in the 3'- to 5'-direction, producing 5'-mononucleotides. Applications include eliminating residual single-stranded DNA containing a 3'-terminus, measuring endonucleolytic cleavage of covalently closed circular (ccc) ssDNA, measuring DNA helicase activity.

Supplier: MP Biomedicals

Activity: 10 units/mg solid or more (containing approx. 20% of stabilisers). Unit definition: One unit causes the formation of one micromole of hydrogen peroxide per minute at pH 8,0 at 37 °C. Ref.: P.J.G. Mann and J.H. Quastel, Biochem. J., 31: 869 (1937)

Supplier: MP Biomedicals

Activators: Papain is activated by cysteine, sulphide, sulphite and more. It is enhanced when heavy metal binding agents such as EDTA are also present. N-bromosuccinimide enhances the activity. Inhibitors: Substances which react with sulphydryl groups including heavy metals, carbonyl reagents. Aldehydes are papain inhibitors. Benzoylamidoacetonitrile is an inhibitor. See Shapira and Arnon (1967a and b) on antibody inhibitors. Papain may be inactivated by H₂O₂ generated by γ-irradiation of H₂O⁻ the active SH group being oxidised to sulphenic acid. Specific inhibitors are AEBSF, antipain, cystatin, E-64, leupeptin, PMSF, TLCK and TPCK.

Supplier: MP Biomedicals

Inhibitors: p-Chloromercuribenzoate, iodoacetamide, heavy metal ions (Zn²⁺, Fe²⁺, Zn²⁺, Cd²⁺, Cu²⁺, Pb²⁺, Ag⁺, Hg²⁺), ionic Detergents (SDS, DAC, etc.). Contaminants: The preparation is practically free from other glycosidases (a-galactosidase, a-,b-glucosidase, a-,b-mannosidase, etc.) and proteinase. Principle: o-Nitrophenyl-b-D-galactopyranoside (ONPG) b-galactosidase > o-Nitrophenol (ONP) + D-Galactose. The appearance of o-nitrophenol is measured at 410 nm by spectrophotemetry. Thermal Stability: Below 50 °C (pH 7,3; 15 min) (Lit.), Optimum Temperature: 50 to 55 °C (Lit.).

Supplier: MP Biomedicals

Elastase is prepared from porcine pancreas. It is lyophilised and water soluble. Elastase is chromatographically prepared by the method of Narayanan and Anwar. In the method, 2 times crystalline elastase is adsorbed on a column of DEAE-Sephadex A50 to separate elastase and non-specific protein components. The elastase component is further purified by chromatography on a column of CM-Cellulose using a sodium chloride gradient to elute the elastase. The latter is dialysed until chloride-free and then lyophilised. During its preparation the elastase is held below a pH of 5,5 for greater than 24 hours. Two times crystallised from the euglobin fraction of porcine pancreas by the method of Lewis et al. Does not contain trypsin or chymotrypsin.

Supplier: MP Biomedicals

Preparation Method
Produced from 3× crystallised chymotrypsinogen

α-Chymotrypsin is used for treating pancreatic insufficiency and in traumatology.

Chymotrypsin preferentially catalyses the hydrolysis of peptide bonds involving L-isomers of tyrosine, phenylalanine, and tryptophan. It also readily acts upon amides and esters of susceptible amino acids. In addition to bonds involving aromatic amino acids, chymotrypsin catalyses at a high rate the hydrolysis of bonds of leucyl, methionyl, asparaginyl, and glutamyl residues. a-Chymotrypsin is a protein consisting of 241 amino acid residues. The molecule has three peptide chains: an A chain of 13 residues, a B chain of 131 residues, and a C chain of 97 residues.

Supplier: MP Biomedicals

Aldolase is a tetrameric protein. It catalyses a key reaction in glycolysis and energy production:D-Fructose 1,6-bisphosphate aldolase → dihydroxyacetone phosphate + D-glyceraldehyde-3-phosphate. Aldolase is present in all animal tissue and in most microorganisms. There are two classes of aldolases. Class I aldolase is found in animal and higher plant tissue. Class II aldolase is found in primitrive cells such as yeasts and bacteria. Class I aldolase is characterised by not requiring a bivalent metal cofactor and the formation of a ketimine Schiff base intermediate with the substrate dihydroxyacetone phosphate. Class II aldolase requires a metal cofactor and is inhibited by EDTA. Three types of aldolase exist in animal tissue. The major form, type A is found in muscle; type B is found in liver tissue and type C (plus some type A) is found in brain tissue. Aldolase forms five isozymes which may to various degrees be organ specific.

Supplier: Chemicon

L-Lactate dehydrogenase (from Muscle)

Supplier: Chemicon

Chicken lysozyme (Muramidase) (from egg white)

Supplier: Chemicon

Penicillinase (beta-Lactamase) (from Enterobacter cloacae)

Supplier: Chemicon

Human lysozyme (Muramidase) (from Milk)

Supplier: Chemicon

Bovine Ribonuclease A (from Pancreas)

Supplier: Chemicon

Bovine trypsin (from pancreas)

Supplier: Chemicon

Penicillinase (beta-Lactamase)

Supplier: Chemicon

Pig Pepsin (from Gastric mucosa)

Supplier: Chemicon

Human Trypsin (from pancreas)

Supplier: LGC Standards PROMOCHEM

Pepsin

Supplier: EUROCLONE

Lysozyme (Muramidase)

Supplier: LGC Standards PROMOCHEM

Trypsin

Supplier: C LECTA

DENARASE High Salt is an engineered version of the wild-type Serratia marcescens endonuclease, which is commonly used for DNA removal applications in bioprocessing. Compared to the wild-type DENARASE, a few amino acids were substituted to provide the enzyme with an improved salt tolerance without losing its specificity for nucleic acids.

Supplier: LGC Standards PROMOCHEM

Cellulase

Supplier: Thermo Fisher Scientific

Pancreatin

Supplier: EUROCLONE

Desoxyribonuclease I

Supplier: EUROCLONE

Proteinase K

Supplier: EUROCLONE

Ribonuclease A

Supplier: MEGAZYME

Linamarase (beta-D-Glucosidase)

Supplier: EUROCLONE

DNase-free.

Supplier: EUROCLONE

Trypsin

Supplier: LGC Standards PROMOCHEM

Bromelain (from stem)