Nobuhiko Katunuma

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A series of new epoxysuccinyl peptides were designed and synthesized to develop a specific inhibitor of cathepsin B. Of these compounds, N-(L-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-isoleucyl-L-proli ne (compound CA-030) and N-(L-3-trans-propylcarbamoyloxirane-2-carbonyl)-L-isoleucyl-L-prol ine (compound CA-074) were the most potent and specific(More)
From the lysosomal cysteine proteinase cathepsin B, isolated from human liver in its two-chain form, monoclinic crystals were obtained which contain two molecules per asymmetric unit. The molecular structure was solved by a combination of Patterson search and heavy atom replacement methods (simultaneously with rat cathepsin B) and refined to a(More)
New derivatives of E-64 (compound CA-030 and CA-074) were tested in vitro and in vivo for selective inhibition of cathepsin B. They exhibited 10,000-30,000 times greater inhibitory effects on purified rat cathepsin B than on cathepsin H and L: their initial Ki values for cathepsin B were about 2-5 nM, like that of E-64-c, whereas their initial Ki values for(More)
The ADP-ribosylating toxins (ADPRTs) produced by pathogenic bacteria modify intracellular protein and affect eukaryotic cell function. Actin-specific ADPRTs (including Clostridium perfringens iota-toxin and Clostridium botulinum C2 toxin) ADP-ribosylate G-actin at Arg-177, leading to disorganization of the cytoskeleton and cell death. Although the(More)
A novel trypsin-like protease associated with rat bronchiolar epithelial Clara cells, named Tryptase Clara, was purified to homogeneity from rat lung by a series of standard chromatographic procedures. The enzyme has apparent molecular masses of 180 +/- 16 kDa on gel filtration and 30 +/- 1.5 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis(More)
Human poly(ADP-ribose) synthetase consists of three proteolytically separable domains, the first for binding of DNA, the second for automodification, and the third for binding of the substrate, NAD (Ushiro, H., Yokoyama, Y., and Shizuta, Y. (1987) J. Biol. Chem. 262, 2352-2357). We have isolated and sequenced cDNA clones for the enzyme using synthesized(More)
Papain was used as an experimental model structure to understand the inhibition mechanism of newly developed specific inhibitors of cathepsin L, the papain superfamily. Recently, we developed a series of cathepsin L-specific inhibitors which are called the CLIK series [(1999) FEBS Lett. 458, 6-10]. Here, we report the complex structure of papain with(More)
Asparagine-linked sugar chains of rat kidney aminopeptidase N and dipeptidylpeptidase IV were investigated comparatively. Oligosaccharides released from the two enzymes by hydrazinolysis were fractionated by paper electrophoresis, serial chromatographies on columns of immobilized Aleuria aurantia lectin, concanavalin A, phytohemagglutinin E4, and Datura(More)
Iota-toxin from Clostridium perfringens type E is an ADP-ribosylating toxin (ADPRT) that ADP-ribosylates actin, which is lethal and dermonecrotic in mammals. It is a binary toxin composed of an enzymatic component (Ia) and a binding component (Ib). Ia ADP-ribosylates G-actin at arginine 177, resulting in the depolymerization of the actin cytoskeleton. Here,(More)