Minagawa S, Ishida M, Shimakura K, Nagashima Y, Shiomi K
Department of Food Science and Technology, Tokyo University of Fisheries, Japan.
Comp Biochem Physiol B Biochem Mol Biol. 1997 Oct;118(2):381-6. doi: 10.1016/s0305-0491(97)00174-0.
Two protease inhibitors (AXPI-I and -II) were isolated from the sea anemone Anthopleura aff. xanthogrammica by a combination of acetone precipitation, gel filtration on Sephadex G-75, cation-exchange fast protein liquid chromatography (FPLC) on Mono S and reverse-phase HPLC on TSKgel ODS-120T. Both inhibitors are basic polypeptides, and their amino acid compositions are characterized by the presence of six half-Cys residues and the absence of Met and Trp. They are potently active against trypsin; inhibition of other serine proteases (alpha-chymotrypsin and elastase) is also displayed by only AXPI-I. However, the inhibitors show no affinity for metallo-proteases and cysteine proteases. Analyses of the N-terminal portion and enzymatic fragments established their complete amino acid sequences comprising 58 residues. The overall sequence homology and the conserved location of all half-Cys residues confirmed that the A. aff. xanthogrammica inhibitors belong to the Kunitz-type family.
通过丙酮沉淀、Sephadex G-75凝胶过滤、Mono S阳离子交换快速蛋白质液相色谱（FPLC）以及TSKgel ODS-120T反相高效液相色谱相结合的方法，从海葵拟黄斑海葵（Anthopleura aff. xanthogrammica）中分离出两种蛋白酶抑制剂（AXPI-I和AXPI-II）。这两种抑制剂均为碱性多肽，其氨基酸组成的特点是含有6个半胱氨酸残基，且不含甲硫氨酸和色氨酸。它们对胰蛋白酶具有强效活性；只有AXPI-I对其他丝氨酸蛋白酶（α-胰凝乳蛋白酶和弹性蛋白酶）也有抑制作用。然而，这些抑制剂对金属蛋白酶和半胱氨酸蛋白酶没有亲和力。对N端部分和酶切片段的分析确定了它们完整的氨基酸序列，由58个残基组成。整体序列同源性以及所有半胱氨酸残基的保守位置证实，拟黄斑海葵抑制剂属于Kunitz型家族。
