Endogenous inhibitors of lysosomal proteinases.

Endogenous inhibitors of lysosomal proteinases.

Specific inhibitors of three lysosomal proteinases are present in the cytosolic and lysosomal compartments of rabbit liver. The cytosolic inhibitors, purified by chromatography on DEAE-Trisacryl and Sephadex G-75, show specificities toward cathepsin M, cathepsins B and L, and fructose 1,6-bisphosphatase converting enzyme (CE), respectively, and are designated IM, IB/L, and ICE. Inhibitors with ...

Aspartic proteinases and their inhibitors.

Proteolytic enzymes are classified on the basis of their catalytic mechanism as belonging to one of four groups: the serine, cysteine, metallo and aspartic proteinases (Kay, 1982). In contrast to the detailed sequence information and three-dimensional structures that have been produced for many enzymes belonging to the first three groups, relatively little is known about the aspartic proteinase...

Amino acid substitutions in the N-terminal segment of cystatin C create selective protein inhibitors of lysosomal cysteine proteinases.

We used site-directed mutagenesis to alter the specificity of human cystatin C, an inhibitor with a broad reactivity against cysteine proteinases. Nine cystatin C variants containing amino acid substitutions in the N-terminal (L9W, V10W, V10F and V10R) and/or the C-terminal (W106G) enzyme-binding regions were designed and produced in Escherichia coli. It was discovered that the inhibition profi...

Endogenous growth promotors and inhibitors in tahiti lime

The synthesis of peptidylfluoromethanes and their properties as inhibitors of serine proteinases and cysteine proteinases.

A synthesis of peptidylfluoromethanes is described that utilizes the conversion of phthaloyl amino acids into their fluoromethane derivatives. These can be deblocked and elongated. The inactivation of chymotrypsin by Cbz-Phe-CH2F (benzyloxycarbonylphenylalanylfluoromethane) was found to be considerably slower than that of the analogous chloromethane. The fluoromethane analogue inactivates chymo...