Studies on Biologically Active Peptides Produced by Phytoplankton

点击翻译按钮获取中文摘要

1. Screening of biologically active peptidesAlgal samples of twenty four species and strains were collected and cultured. They were searched for angiotensin-converting enzyme, papain, elastase, trypsin and chymotrypsin inhibitory activities in their water-soluble and fat-soluble fractions. Water-soluble fractions of eleven species and fat-soluble fractions of eight species showed angiotensin-converting enzyme inhibitory activities. Water-soluble fractions of fourteen species and fat-soluble fractions of twenty three species inhibited papain activities. Water-soluble fraction of a species and fat-soluble fractions of two species inhibited elastase activities. Water-soluble fractions of five species and fat-soluble fractions of eleven species inhibited trypsin activities. Water-soluble fractions of five species and fat-soluble fractions of eight species inhibited chymotrypsin activities.2. Isolation and structural elucidation of angiotensin-converting enzyme inhibitory peptidesAngiotensin-converting enzyme inhibitors were isolated from water-soluble fractions of chlorophytes Dunaliella bardawil and Botryococcus braunii. These inhibitors were suggested to be peptides from the results of the hydrolysates amino acid analyses. They inhibited angiotensin-converting enzyme at 50 mug/ml.An angiotensin-converting enzyme inhibitor was isolated from the cyanophyte Microcystis aeruginosa by ion exchange and reverse phase chromatography. Its structure was determined as 1 by using amino acid analysis, FABMS and 2D NMR spectrum. The inhibitor includes a novel amino acid, 2-amino-3-hydroxy-8-methylnonanoic acid. It inhibited angiotensin-converting enzyme at 7 mug/ml.