Chymotrypsin-like enzyme

Total PA activity Total PA activity Collagenase 1 Collagenase 1 CB-Iike enzyme Trypsin-like enzyme Chymotrypsin-like enzyme 92-kDa gelatinase Heparanase... 

There is evidence that protein structures are also responsible for cell cohesion in nonpalmo-plantar stratum corneum. When punch biopsies of normal human gluteal skin were incubated in a buffer containing a mixture of the zwitterionic surfactant /V,/V,-dimethyldodecylamine and the anionic surfactant sodium dodecyl sulfate,11 there was dissociation of cells in the stratum corneum but not in the rest of the epidermis. The cell dissociation took place only in the presence of EDTA and was inhibited by the serine protease inhibitor aprotinin.12 Suzuki et al.13,14 presented evidence that spontaneous cell dissociation in nonpalmo-plantar stratum corneum could be inhibited by a combination of inhibitors of trypsin-like and chymotrypsin-like enzymes. Thus, nonpalmo-plantar stratum corneum contains endogenous proteases that mediate cell dissociation. 

Lundstrom, A. and Egelrud, T., Cell shedding from plantar skin in vitro evidence that two different types of protein structures are degraded by a chymotrypsin-like enzyme, Arch. Dermatol. Res., 282, 234, 1990. 

Higuchi, K., Kajiki, A., Nakamura, M., Harada, S., Pula, P.J., Scott, A.L., Dannenberg, A.M., Jr. (1988). Proteases released in organ culture by acute dermal inflammatory lesions produced in vivo in rabbit skin by sulfur mustard hydrolysis of synthetic peptide substrates for trypsin-like and chymotrypsin-like enzymes. Inflammation 12 311-34. 

K., Neurath, H. and Woodbury, RG. (1985). Mammalian chymotrypsin-like enzymes. Comparative reactivities of rat mast cell proteases, human and dc skin proteases and human cathepsin G with peptide-4-nitroanilide substrates and with peptide chloromethyl ketone and sulphonyl fluoride inhibitors. Biochemistry 24, 2048-2058. 

Wintroub, B.U., Kaempfer, C.E., Schechter, N.M. and Proud, D. (1986a). Human lung mast cell chymotrypsin-like enzyme identification and partial characterization. J. Clin. Invest. 77, 196-201. 

The 8-endotoxins and the other Bt toxins function only as stomach poisons. A susceptible insect must eat them, and the crystals dissolve in the midgut. This solubilization is sometimes dependent on chymotrypsin-like enzymes. The protoxin is further attacked by proteolytic enzymes present in the gut that convert it to the active toxin. An interesting and unexpected finding is that DNA is intimately associated with the toxin crystal and appears to play a role in the proteolytic processing. 

Cathepsin G. Isoln from human spleen G. Starkey et al, Biochem. J. 155, 255 (1976). Chymotrypsin-like enzyme. Catalytic and immunological properties P. M. Starkey, A. J. Barrett, ibid. 273. 

Johnston, K.A., Fee, M., Brough, C., Hilder, V.A., Gatehouse, A.M.R. and Gatehouse, J.A. (1995). Protease activities in the larval midgut of Heliothis virescens Evidence for trypsin and chymotrypsin-like enzymes. Insect Biochem. Mol. Biol. 25,375-383. 

Figure 5. Comparison of residual activities of (a) trypsin-like, and (b) chymotrypsin-like enzymes in pressurized intact fish tissues versus pressurized tissue-free enzyme extracts.

In this assay, enzymes with chymotrypsin-like specificity readily bind the side chain of Phe at the primary substrate binding site (SI) and subsequently hydrolyze the adjacent amide bond linking the Phe residue to the p-NA moiety. On cleavage, the release of p-NA is measured by the increase in absorbance at 410 nm (e4l0 = 8480 M 1 cm-1) with time, using a recording spectrophotometer. 

In 2007 a series of p-lactam derivatives was designed and synthesized to inhibit the chymotrypsin-like activity of the human 20S proteasome. The most potent compounds of this new structural class of p-subunit exhibit good selectivity over the trypsin-like and post-glutamyl-peptide hydrolytic activities of the enzyme [409],... 

The chymotrypsin-like HCV NS3 protease is an essential enzyme in the fife cycle of the hepatitis C virus. An estimated 3% of the world population is infected by hepatitis C and it is the leading cause of chronic fiver disease and the primary indication for fiver transplantation [82], The HCV NS3 protease is therefore considered an important pharmaceutical target. 

One goal in the design of an inhibitor is specificity. Often this is a considerable challenge since physiological systems contain a number of closely related proteases. For example, there are at least four chymo-trypsin-like enzymes in humans. These include pancreatic chymotrypsin, cathepsin G, and two mast cell proteases (the human enzymes have not been characterized yet, but two are found in rats). All of these enzymes... 

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