8GCH
GAMMA-CHYMOTRYPSIN IS A COMPLEX OF ALPHA-CHYMOTRYPSIN WITH ITS OWN AUTOLYSIS PRODUCTS
Summary for 8GCH
| Entry DOI | 10.2210/pdb8gch/pdb |
| Descriptor | GAMMA-CHYMOTRYPSIN A, GLY ALA TRP PEPTIDE, SULFATE ION, ... (6 entities in total) |
| Functional Keywords | hydrolase, serine proteinase, hydrolase-peptide complex, hydrolase/peptide |
| Biological source | Bos taurus (cattle) More |
| Cellular location | Secreted, extracellular space: P00766 P00766 P00766 |
| Total number of polymer chains | 4 |
| Total formula weight | 25979.17 |
| Authors | Harel, M.,Sussman, J.L.,Silman, I. (deposition date: 1991-03-27, release date: 1992-04-15, Last modification date: 2024-11-13) |
| Primary citation | Harel, M.,Su, C.T.,Frolow, F.,Silman, I.,Sussman, J.L. Gamma-chymotrypsin is a complex of alpha-chymotrypsin with its own autolysis products. Biochemistry, 30:5217-5225, 1991 Cited by PubMed Abstract: The determination of three separate gamma-chymotrypsin structures at different temperatures and resolutions confirmed the presence of electron density in the active site, which could be interpreted as an oligopeptide as had previously been suggested by Dixon and Matthews [(1989) Biochemistry 28, 7033-7038]. HPLC analyses of the enzyme before and after crystallization demonstrated the presence of a wide variety of oligopeptides in the redissolved crystal, most with COOH-terminal aromatic residues, as expected of the products of chymotrypsin cleavage, which appeared to arise from extensive autolysis of the enzyme under the crystallization conditions. The refined structures agree well with the conformation of both gamma-chymotrypsin and alpha-chymotrypsin. The electron density in the active site is thus interpreted as arising from a repertoire of autolysed oligopeptides produced concomitantly with crystallization. The COOH-terminal carbons of the polypeptide(s) display short contact distances (1.97, 2.47, and 2.13 A, respectively) to Ser195 O gamma in all three refined structures, but the electron density is not continuous between these two atoms in any of them. This suggests that some sequences are covalently bound as enzyme intermediates while others are noncovalently bound as enzyme-product complexes. PubMed: 2036388DOI: 10.1021/bi00235a015 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.6 Å) |
Structure validation
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