Trypsin distribution

Figure 21.5 (a) Distribution of trypsin-induced peptides generated from the digestion... 

Braun, V. and Rehn, K. (1969). Chemical characterization, spatial distribution and function of a lipoprotein (murein-lipoprotein) of the E. coli cell wall. The specific effect of trypsin on the membrane structure, Eur. J. Biochem., 10, 426-438. 

Trypsin inhibitors in cucumber were first found in a study by Walker-Simmons et /. " after wounding of leaves and treatment with proteinase inhibitor-inducing factor (PIIF). The amino acid sequence of two inhibitors isolated from Cucurhita maxima (winter squash) were determined by Wilusz et at The peptides named ITD I and ITD 111 each comprised a 29-residue sequence with six cysteine residues. The only difference between the two peptides is in position 9, which is lysine in ITD I and glutamic acid in ITD III. The reactive site is located at the peptide bond between Arg5 and Ile6. Owing to their discovery and distribution in Cucurbitaceae the inhibitor family has been named squash inhibitors. Since the initial discoveries many other members of the squash family have been found. 

Fourier transform infrared/photoacoustic spectroscopy (FT-IR/PAS) can be used to evaluate the secondary structure of proteins, as demonstrated by experiments on concanavalin A, hemoglobin, lysozyme, and trypsin, four proteins having different distributions of secondary... 

The heat stability of glutaminase-asparaginase modified with glu-taraldehyde-activated glycopeptides was slightly greater than that of the native enzyme, as was its susceptibility to trypsin.108 This modification decreased the pi by several pH units, and altered the association behavior the glycosylated enzyme had a much wider distribution of molecular weights as determined by sedimentation equilibrium. 

St. Leger, R. J., Cooper, R. M., and Chamley, A. K. (1987b). Distribution of chymoelastases and trypsin-like enzymes in five species of entomopathogenic deuteromycetes. Archives of Biochemistry and Biophysics, 258, 123-131. 

C-Methyl-/3-Casein. 14C-Labeled proteins prepared by reductive methylation have potential as substrates in the study of proteolytic enzymes. A serious limitation is that complete methylation of lysine residues results in inhibition of proteolysis by enzymes with trypsin-like specificity (13). It was interesting to determine whether this problem could be overcome by incomplete methylation which left unaltered most of the lysine residues in more or less random distribution throughout the protein. /3-Casein was selected as a suitable protein for this study since it is cleaved by trypsin-like enzymes to well characterized fragments, the y-caseins, in addition to less well characterized fragments, the proteose peptones. We anticipated that this type of study could provide a basis for a general investigation of milk protein transformation by the native milk proteinase which has a specificity similar to trypsin (14). 

The H/D exchange pattern for peptide N-H groups of crystalline trypsin, displayed schematically in Fig. 19.17, shows clearly that the H/D exchange is not evenly distributed among secondary N-H - -0=C hydrogen bonds. Some are fully... 

Fig. 37. Distribution of energies of water molecules about bovine pancreatic trypsin inhibitor in the crystal. Total energy ( ) partitioned into contribution from water-water (D) water-protein (O) interactions. From Hermans and Vacatello (1980).

Figure 3.9. x-Variable distribution for the 10 grid probes in the P pocket after BUW. Blue dots indicate energies in thrombin, red dots in trypsin, and green dots in factor Xa. 

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