A novel peptide inhibitor of the myosin ATPase from an Okinawan marine sponge.
A substance which inhibits the myosin ATPase has been detected from an Okinawan marine sponge. The inhibitor has been isolated from the methanol-soluble extract of the sponge by gel filtration and hydrophobic chromatography. The isolated inhibitor is an amphipathic peptide, which is rich in Asp, Glu, Ser, and Gly, and devoid of Met and Trp. The molecular weight of the peptide is about 6300 as determined by gel filtration, amino acid analysis, and sodium dodecyl sulfate-gel electrophoresis. The peptide is a potent inhibitor not only for the K+-, Ca2+-, and Mg2+-ATPases of myosin, its subfragment-1, and actomyosin, but also for superprecipitation of actomyosin, inhibiting them completely in the range of 10-400 ng/ml. The peptide inhibitor may provide a useful tool to elucidate the structure-function relationship of the myosin ATPase.
Hiratsuka
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Department of Chemistry, Asahikawa Medical College, Hokkaido, Japan.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004791:Enzyme Inhibitors / Q000302:isolation & purification*; D007564:Japan; D007700:Kinetics; D008970:Molecular Weight; D009218:Myosins / Q000037:antagonists & inhibitors*; D010455:Peptides / Q000302:isolation & purification* / Q000494:pharmacology; D011161:Porifera / Q000032:analysis*; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D000596:Amino Acids; D004791:Enzyme Inhibitors; D010455:Peptides; D009218:Myosins