Molecular dynamics (MD) simulations are the classic single-molecule "experiments," providing atomic-resolution structural and dynamic information. However, the single-molecule nature of the technique has also been its shortcoming, with frequent criticisms of sampling inadequacies and questions regarding the ensemble behavior of large numbers of molecules. Given the increase in computer power, w...

Microcomplement fixation was employed to compare the immunological differences that occur between purified inhibitor I from potato tubers, the four purified protomers that comprise it, and inhibitor I from tuber and leaf extracts. Total inhibitors of chymotrypsin and trypsin in leaves of seven genera of the Solanaceae were identified by enzymatic assay. In leaves of three genera, Solanum, Lycop...

Three peptides modelling a highly potent, 35-residue chymotrypsin inhibitor (Schistocerca gregaria chymotrypsin inhibitor) were designed and synthesized by convergent peptide synthesis. For each model peptide, the inhibitory constant (Ki) on chymotrypsin and the solution structure were determined. In addition, molecular dynamics calculations were performed for all of them. Two models containing...

We have performed 128 folding and 45 unfolding molecular dynamics runs of chymotrypsin inhibitor 2 (CI2) with an implicit solvation model for a total simulation time of 0.4 microseconds. Folding requires that the three-dimensional structure of the native state is known. It was simulated at 300 K by supplementing the force field with a harmonic restraint which acts on the root-mean-square deviat...

The capacity for self-polymerization and shape of the tubulin polymers assembled after digestion with trypsin, Pronase, chymotrypsin, subtilisin, Staphylococcus aureus proteinase V8 and proteinase K were investigated. Digestion with trypsin, Pronase or chymotrypsin resulted in a decrease in the ability of tubulin for self-assembly, whereas limited proteolysis with subtilisin, S. aureus proteina...

This paper reports on the presence of a strong binding site for the dye Biebrich Scarlet, (6-[Z-hydroxy-l-naphthyl]azo)3,4’-azodibenzene sulfonic acid, on cr-chymotrypsin. The 1: 1 protein-dye complex is characterized by a Kdiss of 8.8 f 0.1 X 10U5 M in 0.1 M phosphate buffer at pH 7.6 and W’. Complex formation is associated with a red shift in the visible spectrum of the dye, and a characteris...

A comparative study was performed on the conformational stabilities of trypsin and α-chymotrypsin. At 45oC, trypsin was most stable at pH 3, while the highest stability of αchymotrypsin was observed at pH 5. With both ester and amide substrates, trypsin displayed activation at pH 3. In the case of α-chymotrypsin, activation was detected at pH 5 only with the amide substrate. The time curves of ...

Suc-Tyr-Leu-Phe-pNA is a good substrate for human leukocyte cathepsin G and achymotrypsin but not for human leukocyte elastase(HLE).However,Suc-Tyr-D-Leu-D-Phe-pNA inhibited not only cathepsin G and a-chymotrypsin but also HLE(Ki values,1.1,0 .94 and0.16mM, respectively).The p-nitroanilide(pNA)moiety of Suc-Tyr—Leu—Phe-pNA and Suc-Tyr-D-Leu-DPhe-pNA was substituted with p-benzoylaniline(BZA) ,p...

A recent report [Atassi, M. Z. and Manshouri, T. (1993) Proc. Natl. Acad. Sci. USA 90, 8282-8286] described the design and synthesis of two 29-amino acid cyclic peptides that were reported to hydrolyze both ester and amide bonds with chymotrypsin-like or trypsin-like specificity. We have synthesized the trypsin-mimic peptide (TrPepz) and detect no activity toward either ester or peptide substra...

Considerable practical importance is attached to the mode of inhibition of chymotrypsin by diisopropyl fluorophosphate (DFP), because it is evident that this inhibition reaction, fairly general among esterases, may furnish a clue to the nature of the active grouping in this enzyme, and may also explain the mechanism of the toxicity of DFP together with a number of related substances whose indus...