title: A cysteine-rich serine protease inhibitor (Guamerin II) from the non-blood sucking leech Whitmania edentula: biochemical characterization and amino acid sequence analysis.
abstract: A cysteine-rich serine protease inhibitor (Guamerin II) was isolated from the non-blood sucking leech Whitmania edentula. The new inhibitor was identified as a low molecular weight (6,012 Da) polypeptide with some sequence similarities to antistasin, hirustasin and guamerin. The inhibitor contained 56 amino acid residues with 76.8% sequence similarity to guamerin, 48.2% to hirustasin and 28.6% to the first domain of antistasin. This new inhibitor was the first completely sequenced serine protease inhibitor from a non-blood sucking leech. Analysis of the inhibitor revealed that it was active against neutrophil elastase and chymotrypsin, but had no activity against a variety of other proteases. The P1 reactive site residue was identified as methionine and the residues surrounding the P1 site were hydrophobic amino acids. The primary structure of the inhibitor showed no similarity to well-known elastase inhibitors from leeches such as eglin.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Taejon, Korea.
authors.forename: D R
authors.initials: DR
authors.lastname: Kim
authors.forename: S J
authors.initials: SJ
authors.lastname: Hong
authors.forename: K S
authors.initials: KS
authors.lastname: Ha
authors.forename: C O
authors.initials: CO
authors.lastname: Joe
authors.forename: K W
authors.initials: KW
authors.lastname: Kang
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D003545:Cysteine / Q000737:chemistry / Q000235:genetics; D006801:Humans; D007447:Invertebrate Hormones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D007865:Leeches / Q000378:metabolism; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors; D008969:Molecular Sequence Data; D009656:North America; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D013552:Swine
chemical_list: D000596:Amino Acids; D007447:Invertebrate Hormones; D015842:Serine Proteinase Inhibitors; C093975:guamerin; D002918:Chymotrypsin; D019272:Leukocyte Elastase; D003545:Cysteine