Invasive microorganisms efface enteric microvilli to establish intimate contact with the apical surface of enterocytes. To understand the molecular basis of this effacement in amebic colitis, we seeded Entamoeba histolytica trophozoites on top of differentiated human Caco-2 cell layers. Western blots of detergent lysates from such cocultures showed proteolysis of the actin-bundling protein vill...

Two peptide derivatives of arginylfluoromethane (Arg-CH2F), namely Bz(benzoyl)-Phe-ArgCH2F and D-Phe-Pro-Arg-CH2F, have been synthesized by extension of available methods, i.e. the Dakin-West reaction [Rasnick (1985) Anal. Biochem. 149, 461-465] or synthesis of a phthaloyl-blocked C-terminal fluoromethane [Rauber, Angliker, Walker & Shaw (1986) Biochem. J. 239, 633-640; Angliker, Wikström, Raub...

Cysteine proteinases (CPs) are synthesized as zymogens and converted to mature proteinase forms by proteolytic cleavage and release of their pro domain peptides. A cDNA encoding a papain-like CP, called hgcp-Iv, was isolated from a Heterodera glycines J2 cDNA library, expressed and utilized to assess the ability of its propeptide to inhibit proteinase in its active form. The hgcp-Iv cDNA sequen...

Proteinase Inhibitors: Medical and Biological Aspects (Katunuma, N., ed.), pp. 97-109, Springer-Verlag Co., New York Roisen, F. J., Wilson, F. J., Yorke, G., Inczedy-Marcsek, M. & Hirabayashi, T. (19836) J. Muscle Res. Cell. Motility 4, 163-175 Schwartz, W. N. & Bird, J . W. C. (1977) Biochem. J . 167,811 -820 St. John, A. C., McElligott, M. A., Lee, J. A., Keaton, K. S., Yorke, G . , Roisen, F...

Adult Schistosoma mansoni parasites synthesize and secrete both cathepsin L and cathepsin B cysteine proteinases. These cysteine proteinase activities, believed to be involved in hemoglobin digestion by adult schistosomes, were characterized by using specific fluorogenic peptide substrates and zymography. Both cathepsin L- and B-like activities with pH optima of 5.2 and 6.2, respectively, predo...

Human cathepsin B was purified by affinity chromatography on the semicarbazone of Gly-Phe-glycinal linked to Sepharose 4B, with elution by 2,2'-dipyridyl disulphide at pH 4.0. The product obtained in high yield by the single step from crude starting material was 80-100% active cathepsin B. The possibility that this new form of affinity chromatography may be of general usefulness in the purifica...

Calpains are calcium-dependent cysteine proteinases found in all living organisms and are involved in diverse cellular processes. Calpain-like proteins have been reported after in silico analysis of the Tritryps genome and are believed to play important roles in cell functions of trypanosomatids. We describe the characterization of a member of this family, which is differentially expressed duri...