Jung H I, Kim S I, Ha K S, Joe C O, Kang K W
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Taejon.
J Biol Chem. 1995 Jun 9;270(23):13879-84. doi: 10.1074/jbc.270.23.13879.
A new human leukocyte elastase inhibitor was extracted and purified from a Korean native leech Hirudo nipponia. The inhibitor, called guamerin, has a molecular weight of 6,110 and shows inhibition constant (Ki) of 8.1 x 10(-14) M. It is stable at a wide range of pH from 1 to 11 and heat-stable up to 90 degrees C. The complete amino acid sequence of guamerin reveals a cysteine-rich polypeptide of 57 amino acid residues that shows no similarity to any known elastase inhibitors but has 51% sequence homology with hirustasin. Guamerin has identical spacing of 10 cysteine residues as antistasin-type serine proteinase inhibitors, but the P1 reactive site residue is Met36 instead of Arg. The neighboring sequence of the reactive site consists primarily of hydrophobic amino acid residues. Based on examinations of the target proteinases and the reactive site specificity, guamerin is a new low molecular weight protein that inhibits elastases.
从韩国本土水蛭日本医蛭中提取并纯化出一种新型人白细胞弹性蛋白酶抑制剂。该抑制剂名为瓜美林，分子量为6110，抑制常数（Ki）为8.1×10⁻¹⁴ M。它在pH值1至11的广泛范围内稳定，在高达90℃时热稳定。瓜美林的完整氨基酸序列显示为一种富含半胱氨酸的57个氨基酸残基的多肽，与任何已知的弹性蛋白酶抑制剂均无相似性，但与水蛭抑肽酶有51%的序列同源性。瓜美林与抗凝血酶型丝氨酸蛋白酶抑制剂一样，10个半胱氨酸残基的间距相同，但P1反应位点残基是Met36而非Arg。反应位点的相邻序列主要由疏水氨基酸残基组成。基于对靶蛋白酶和反应位点特异性的研究，瓜美林是一种抑制弹性蛋白酶的新型低分子量蛋白质。
