Trypsin proteolysis

Changes in the number of free amino residues alter the modified proteins susceptibility to proteolysis. Albumin chlorination and /V-chloramine formation decreases susceptibility to trypsin digestion. Removing of chloramine residues by treatment with thiosulfate shows that chlorination alters albumin properties by a biphasic mode the reversible chlorination and removal of chloramine moieties markedly increases albumin susceptibility to proteolysis, whereas chlorination produces the irreversible loss of amino moieties and carbonyl group formation effects decrease in albumin susceptibility to trypsin digestion. The effect is related to the number of lost amino residues. A similar relationship was observed for IgG. Fibrinogen and protamine, on the other hand, did not show dependence between chlorination and proneness to trypsin proteolysis (06). 

Leupeptins plasmin and trypsin proteolysis inhibition, thrombokinase ... 

Zierz, S. (1994) Limited trypsin proteolysis renders carnitine palmitoyltransferase insensitive to inhibition by malonyl-CoA in patients with muscle carnitine palmitoyltransferase deficiency. Clin Invest 72 957-960. 

Cytochrome b-559 Lumen-Skeletal Structure. Measurement of the rate of trypsin proteolysis of the COOH-terminal epitope of the cytochrome 6-559 a subunit under conditions where the OEC extrinsic polypeptide are selectively removed (1.0 M NaCl, -16-23 kDa 0.9 M CaCl2, -16, -23, -33 kDa polypeptides 0.8 M Tris, -16, -23, -33 kDa, -Mn). The sensitivity of the 6-559 COOH-terminus to trypsin was markedly... 

Glatter T, Ludwig C, Ahme E, et al. Large-scale quantitative assessment of different in-solution protein digestion protocols reveals superior cleavage efficiency of tandem Lys-C/trypsin proteolysis over trypsin digestion. J Proteome Res. 2012 11 5145-56. doi 10.1021/pr300273g. 

To check if PemB is surface exposed, E. chrysanthemi cells were subjected to proteolysis. Treatment of the cell suspension with trypsin, proteinase K or chimotrypsin at a concentration of 0.1 to 1 mg/ml for 1 h did not cause PemB proteolysis or its liberation into the medium. Cell pre-treatment with EDTA-lysozyme, which renders the periplasmic proteins accessible to proteases, gave no effect. PemB was also resistant to proteolytic digestion in extract of cells disrupted by sonication or in a French press. Only addition of Triton X-100 (up to 0.1%) causing formation of the micelles with PemB lead to a quick proteolyis of this protein (data not shown). In another approach to analyse the PemB exposition, bacterial cells were labelled with sulfo-NHS-biotin. This compound is unable to cross membranes and biotinylation... 

Chapter 4 describes the in vitro reaction of glucose wifh demineralized dentin. Preliminary tests revealed that use of disfilled insfead of deionized water accelerated browning, consistent with the effect of frace metals on the Maillard reaction. The yellow discolored slices were more resistant than controls to pepsin-mediated breakdown, but not to trypsin-mediated breakdown. It would be worthwhile to investigate proteolysis of denfin collagen covalently bound by the Maillard reaction to proteins, which penetrate into a caries lesion. 

Selected entries from Methods in Enzymology [vol, page(s)] Sulfonylation reaction, 11, 706 reaction kinetics, 11, 707 second-order rate constants for inactivation of chymotrypsin, trypsin, and acetylcholine esterase by PMSE and related sulfonylat-ing agents, 11, 707 reactivation of PMS-chymotrypsin, 11, 710 as inhibitor [of calcium-activated factor, 80, 674 of cathepsin G, 80, 565 of crayfish trypsin, 80, 639 of elastase, 80, 587 of pro-lylcarboxypeptidase, 80, 465 of protease Re, 80, 691 of protease So, 80, 695 of protein C, 80, 329] proteolysis, 76, 7. 

Plasmin [EC 3.4.21.7], also known as fibrinase and fibri-nolysin, is a peptidase (a member of the peptidase family SI) that exhibits preferential cleavage at Lys—Xaa > Arg-Xaa (there is actually greater selectivity than displayed by trypsin). Plasmin converts fibrin into soluble products. It is formed from plasminogen by proteolysis, resulting in multiple forms of the active plasmin. 

---