Four kinds of retrovirus protease inhibitors (RPI-856 A, B, C and D) were isolated as white powder from the culture filtrate of a soil isolate, Streptomyces sp. AL-322 by column chromatography using Diaion HP-20, Sephadex LH-20, ODS reversed phase HPLC and SP-2SW ion exchange HPLC. The structures of these inhibitors were elucidated by physico-chemical properties, chemical reactions and spectral...

Novel internally quenched fluorescence peptide substrates containing sequence specific sites for cleavage by multiple proteases were designed and synthesized. The 28 and 29 residue peptides contain an N-terminal fluorescence acceptor group, 4-(4-dimethylaminophenylazo)benzoic acid (DABCYL), and a C-terminal fluorescence donor group, 5-(2-aminoethylamino)naphthalene-1-sulfonic acid (EDANS). Effi...

The angiotensin-I-converting enzyme (ACE) inhibitory peptides from mussel, Mytilus coruscus, were investigated and the variable factors, protease concentration, hydrolysis time, pH, and temperature, were optimized using Uniform Design, a new statistical experimental method. The results proved that the hydrolysate of alkali proteases had high ACE-inhibitory activity, especially the alkali protea...

There is an urgent need for the development of efficient methodologies that accelerate drug discovery. We demonstrate that the strategic combination of fragment linking/optimization and protein-templated click chemistry is an efficient and powerful method that accelerates the hit-identification process for the aspartic protease endothiapepsin. The best binder, which inhibits endothiapepsin with...

Multiple sequence alignment of distantly related viral proteins remains a challenge to all currently available alignment methods. The hidden Markov model approach offers a new, flexible method for the generation of multiple sequence alignments. The results of studies attempting to infer appropriate parameter constraints for the generation of de novo HMMs for globin, kinase, aspartic acid protea...

Small molecule microarrays (SMMs) are proving to be increasingly important tools for assessing protein-ligand interactions, as well as in screening for enzyme substrates and inhibitors, in a high-throughput manner. We previously described an SMM-facilitated screening strategy for the rapid identification of probes against γ-secretase, an aspartic protease. In this article, we extend upon this w...

A cysteine protease was characterized from Symbiodinium sp. strain KB8 isolated from Cassiopea ornata. The protease was purified 36-fold with a yield of 1.8%, by four chromatographic steps using DE-52, DEAE-Toyopearl, MonoQ, and Superdex 200 HR. Among the six substrates tested, the enzyme showed highest activity toward t-butyloxycarbonyl-Val-Leu-Lys-4-methylcoumaryl-7-amide (Boc-VLK-MCA), and Z...