Bovine pancreatic chymotrypsin

Bovine pancreatic chymotrypsin (Mr 25,191) is a protease, an enzyme that catalyzes the hydrolytic cleavage of peptide bonds. This protease is specific for peptide bonds adjacent to aromatic amino acid residues (Trp, Phe, Tyr). The three-dimensional structure of chymotrypsin is shown in Figure 6-18, with functional groups in the active site emphasized. The reaction catalyzed by this enzyme illustrates the principle of transition-state stabilization and also provides a classic example of general acid-base catalysis and covalent catalysis. 

Recently the effects of alcalase (another protease from subtilisin family), bovine pancreatic chymotrypsin, and papain (from papaya) have been evaluated on the desquamatory process.45 Alcalase (or Optimase) is an alkaline serine proteases derived from Bacillus licheniformis with... 

FIGURE 17.10 Effect of bovine pancreatic chymotrypsin on visual scaling after a 3 h occluded application. Vehicle (square), 0.5% chymotrypsin (diamonds), heat inactivated chymotrypsin (triangles). P < 0.05. From El-Kadi, K., Rawlings, A.V., Feinberg, C., Nunn, C., Battaglia, A., Chandar, R, Richardson, N., Sabin, R., and Pocalyko, D. Arch. Dermatol. Res., 293, 500-507, 2001. 

Chymotrypsin has also been utilized to promote debridement, as well as the reduction of soft tissue inflammation. It is also used in some opthalmic procedures, particularly in facilitating cataract extraction. It is prepared by activation of its zymogen, chymotrypsinogen, which is extracted from bovine pancreatic tissue. 

Besides the formation of luminescent silver clusters in fixed cells, likely due to the presence of proteins, fluorescent silver clusters have been synthesized using proteins as templates. In 2008, Pal et al. reported on the use of an enzyme, bovine pancreatic a-chymotrypsin (CHT) as biotemplate during the chemical reduction of... 

V. Schellenberger, U. Schellenberger, Y.V. Mitin, H.D. Jakubke, Characterization of the S -subsite specificity of bovine pancreatic a-chymotrypsin via acyi transfer to added nucieophiles, Eur. J. Biochem. 187(1) (1990) 163-167. 

T. Hugh. Hie preparation and characterization of an active derivative of bovine pancreatic deoxyribonuclease A formed by selective cleavage with a-chymotrypsin. J. BioL Chem. 24 1712-1718 (1973). 

Castro MJ, Anderson S. Alanine point-mutations in die reactive region of bovine pancreatic trypsin inhibitor effects on the kinetics and thermodynamics of binding to beta-trypsin and alpha-chymotrypsin. Biochemistry 1996 35 11435-11446. 

Results of protein-protein docking. aCHYN-a-chymotrypsinogen, a-CHY-a-chymotrypsin, HPTI-human pancreatic trypsin inhibitor, BPTI-bovine pancreatic trypsin inhibitor, CHYI-chymotrypsin inhibitor, Subtilisin l-subtilisin inhibitor D1.3, D44.1, HyHEL5 and HyHELlOare monoclonal antibodies. For further details of coordinates see Cabb et al. [12]. In the table some degenerate identical complexes included our earlier studies have been excluded. 

Aprotinin - which is also known as bovine pancreatic trypsin inhibitor (BPTI) - belongs to the family of Kunitz-type inhibitors, and inhibits serine proteases such as trypsin, chymotrypsin, plasmin, and plasma kaUikrein [15]. Aprotinin consists of 58 amino acids. The aprotinin variant (DesPro(2)-Ser(10)-Arg(15)-Ala(17)-Asp(24)-Thr(26)-Glu(31)-Asn(41)-Glu(53)-aprotinin) was designed by means of rational mutagenesis, and differs from aprotinin by two amino acids in the active site and by seven amino acids in the backbone. The changes in the active site of the aprotinin variant increase the potency towards inhibition of plasma kaUikrein, whereas the inhibition of plasmin is only marginally reduced. 

Figure 8.3 a-Chymotrypsin. (a) Hydrolytic reaction catalyzed by -chymotrypsin, where amino acid residue side chain R2 is hydrophobic or aromatic in character (b) ribbon display structure of a-chymotrypsin (bovine pancreatic) (pdb 4cha) in which key active site residues D102, H57 and S195 (left to right) involved in biocatalysis are shown (yellow) rendered in a tube display style (See Fig. 8.50... 

Also some drug formulations contain more than one enzyme. For example, pancrelipase or Zymase contains amylase (for processing starch), lipase (for breaking down fats), and chymotrypsin (a protease) in various combinations. This protein mixture is isolated from porcine or bovine pancreatic tissues and is sometimes called pancreatin. This enzyme cocktail is sold to help digestion in people who do not produce enough of their own digestive enzymes. Such a condition can arise due to pancreatic disfunction caused by pancreatitis, cystic fibrosis, or pancreatic cancer. 

Figure 7 Correlation between predicted and experimental pK s in nine globular proteins hen egg white lysozyme, ribonuclease A, turkey ovomucid third domain, bovine pancreatic trypsin inhibitor, B1 and B2 immuno obulin G binding domains of protein G, a-chymotrypsin, ribonuclease Tj, lysozyme T4, and staphylococcal nuclease.

CONSENSUS SEQUENCES FOR HUMAN PANCREATIC SECRETORY TRYPSIN INHIBITOR (PSTI) VARIANTS, SELECTED BY PHAGE DISPLAY IN THE pSKAN8 VECTOR, WHICH INHIBIT EITHER BOVINE CHYMOTRYPSIN (CHY) OR HUMAN LEUKOCYTE ELASTASE (HLE) WITH SUBNANOMOLAR K, VALUES (REF. 72 AND P. ROTTGEN AND J. COLLINS, UNPUBLISHED DATA)... 

Chymotrypsin Obtained from purified extracts of bovine or porcine pancreatic tissue. White to tan, amorphous powders soluble in water but practically insoluble in alcohol, in chloroform, and in ether. Major active principle chymotrypsin. Typical application hydrolysis of protein. 

This discussion of the metalloexopeptidases has focused on the general role of these enzymes in the conversion of dietary proteins into amino acids. In particular, the apparent synergistic relationship which the pancreatic carboxypeptidases have with the major endopeptidases, trypsin, chymotrypsin, and pepsin, in order to facilitate formation of essential amino acids has been stressed. The chemical characteristics, metalloenzyme nature, and mechanistic details of a representative of each class of exopeptidase have been presented. Leucine aminopeptidase from bovine lens was shown to be subject to an unusual type of metal ion activation which may be representative of a more general situation. Carboxypeptidase A of bovine pancreas was discussed in terms of its three-dimensional structure, the implications of x-ray crystallography to mecha ... 

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