Kim D R, Hong S J, Ha K S, Joe C O, Kang K W
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Taejon, Korea.
J Enzyme Inhib. 1996;10(2):81-91. doi: 10.3109/14756369609020161.
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.
从非吸血水蛭宽体金线蛭中分离出一种富含半胱氨酸的丝氨酸蛋白酶抑制剂（瓜马林II）。这种新的抑制剂被鉴定为一种低分子量（6012道尔顿）的多肽，与抗凝血酶III、水蛭抑肽酶和瓜马林有一些序列相似性。该抑制剂含有56个氨基酸残基，与瓜马林的序列相似性为76.8%，与水蛭抑肽酶的序列相似性为48.2%，与抗凝血酶III第一个结构域的序列相似性为28.6%。这种新的抑制剂是第一个来自非吸血水蛭的完全测序的丝氨酸蛋白酶抑制剂。对该抑制剂的分析表明，它对中性粒细胞弹性蛋白酶和胰凝乳蛋白酶有活性，但对多种其他蛋白酶没有活性。P1反应位点残基被鉴定为甲硫氨酸，P1位点周围的残基是疏水氨基酸。该抑制剂的一级结构与水蛭中著名的弹性蛋白酶抑制剂如埃格林没有相似性。
