BACKGROUND Lactacystin inhibits cell proliferation and induces a distinctive, predominantly bipolar (two-neurite-bearing) morphology in Neuro 2A murine neuroblastoma cells. It binds with high specificity to the multicatalytic 20S proteasome and inhibits at least three of its peptidase activities (chymotrypsin-like, trypsin-like and peptidylglutamyl-peptide hydrolyzing), each at a different rate...

The structural specificity requirements of chymotrypsin have been well defined and reviewed by several investigators (l-3). As in the case of carboxypeptidase (4), the specific amino acid required in a substrate for chymotrypsin is tyrosine, tryptophan, or phenylalanine, in order of decreasing susceptibility of their corresponding ester or peptide derivatives. The enzyme is reported to attack, ...

We report single-molecule folding studies of a small, single-domain protein, chymotrypsin inhibitor 2 (CI2). CI2 is an excellent model system for protein folding studies and has been extensively studied, both experimentally (at the ensemble level) and theoretically. Conformationally assisted ligation methodology was used to synthesize the proteins and site-specifically label them with donor and...

The dielectric effects on trypsin and a-chymotrypsin activities have revealed that at pH 7.8 the active species of the former is the cation while that of the latter is the anion. The present study on the dielectric effects along the pH-activity curves shows that trypsin remains positive within the pH range of 5.5 to 8.5. Conversely, a-chymotrypsin is positive from pH 5.5 to 6.6, negative from 6...

A cDNA encoding a chymotrypsinogen-like protein in midguts of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) was cloned and sequenced. The 901 bp cDNA contains an 816-nucleotide open reading frame encoding 272-amino acids. The predicted molecular mass and pI of the mature enzyme are 23.7 kDa and 4.64, respectively. The encoded protein includes amino acid sequence m...

The dielectric effects on trypsin and a-chymotrypsin activities have revealed that at pH 7.8 the active species of the former is the cation while that of the latter is the anion. The present study on the dielectric effects along the pH-activity curves shows that trypsin remains positive within the pH range of 5.5 to 8.5. Conversely, a-chymotrypsin is positive from pH 5.5 to 6.6, negative from 6...

A unique nanoporous sol-gel glass possessing a highly ordered porous structure (with a pore size of 153 A in diameter) was examined for use as a support material for enzyme immobilization. A model enzyme, alpha-chymotrypsin, was efficiently bound onto the glass via a bifunctional ligand, trimethoxysilylpropanal, with an active enzyme loading of 0.54 wt%. The glass-bound chymotrypsin exhibited g...

Serine inhibitors have been described in many plant species and are universal throughout the plant kingdom. Trypsin inhibitors are the most common type. In the present study, trypsin and chymotrypsin inhibitory activity was detected in the seed flour extracts of four Egyptian varieties of soybean (Glycine max). The soybean variety, Giza 22, was found to have higher trypsin and chymotrypsin inhi...

The effects of Treponema denticola and its outer membrane-bound chymotrypsin-like proteinase on periodontal ligament epithelial cell cultures at different stages of maturity were studied. In sparse cultures with migrating epithelial cells, large intracellular vacuoles were formed rapidly following exposure to live T. denticola. Treponemes showing structural damage were seen occasionally inside ...

Hartley (4) has reported the amino acid sequence of a 25-residue peptide from the tryptic digest of X-sulfochymotrypsinogen which contains the “active center” serine as well as both methionine residues of a-chymotrypsin (Fig. 1). By kinetic analysis, Ray et al. (5, 6) deduced that 1 of the 2 methionine residues and 1 of the 2 histidine residues in chymotrypsin are rapidly destroyed on photo-oxi...