Yoshinobu Motoki

Antiretroviral activity in a marine red alga: reverse transcriptase inhibition by an aqueous extract of Schizymenia pacifica.

SummaryAn aqueous extract from the marine red alga, Schizymenia pacifica has been tested in a cell free system for its effect on reverse transcriptase from avian retrovirus (avian myeloblastosis virus), and mammalian retrovirus (Rauscher murine leukemia virus). The extract inhibited reverse transcriptase from both these retroviruses but showed almost no effect, if any, on the activity of cellular DNA polymerase alpha and RNA polymerase II in vitro. Consequently it is unlikely to have an adverse effect on the growth of cultured cell. The inhibitory activity of the extract was stable over a relatively wide pH range (pH 1–11) and was not lost after pronase digestion. Inhibitory activity of the extract was lost after boiling at 100°C in 0.67 N HCl, and after treatment with 100 mM NaIO4. The active principle in the extract has an apparent molecular weight in excess of 100 000 daltons. This new reverse transcriptase inhibitor is probably a polysaccharide.

The structure of ancovenin, a new peptide inhibitor of angiotensin I converting enzyme

Abstract The structure of ancovenin, a new peptide inhibitor of angiotensin I converting enzyme, was determined to be a unique tricyclic peptide which comprises sixteen amino acid residues including dehydroalanine and three sulfide amino acids as unusual components.

The Pleiotropic Properties of a Beta-Lactam Antibiotic-Hypersensitive Mutant Derived from Proteus vulgaris IFO 3167

It has been reported that most j3-lactam antibiotic-hypersensitive mutants from Escherichia coli (1), Pseudomonas aeruginosa (3), and Serratia marcescens (6) show pleiotropic properties that are considered to be due to cell surface membrane mutation. The authors found that a mutant from Proteus vulgaris strain also shows similar pleiotropic properties. In the present paper, the authors describe the isolation, sensitivity to various kinds of reagents, and changes of membrane components of a