PURIFICATION AND PROPERTIES OF HUMAN PLACENTAL AMINOPEPTIDASE-B
PURIFICATION AND PROPERTIES OF HUMAN PLACENTAL AMINOPEPTIDASE-B
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DOI：
10.1159/000468885
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发表时间：
1991-01-01
期刊：
影响因子：
--
通讯作者：
TOMODA, Y
中科院分区：
文献类型：
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作者：
NAGATA, Y;MIZUTANI, S;TOMODA, Y
氨肽酶 B（EC 3.4.11.6；L-精氨酰-β-萘酰胺酶）从人胎盘细胞质中纯化 1,800 倍并进行表征。该酶经过硫酸铵分级分离，并在 DE-52、羟基磷灰石、Bio-gel A 0.5 m 和 L-精氨酸-琼脂糖上进行一系列色谱分析。通过凝胶过滤估计该酶的天然分子量为 220,000。在不存在 2-巯基乙醇的情况下，通过 SDS/PAGE 估计分子量约为 83,000，表明该酶以聚合形式存在。该酶的等电点为5.4。纯化的酶在 pH 7.2 时活性最强，以 L-精氨酰-β-萘酰胺为底物，该酶的 K(m) 值为 0.3 mmol/l。人胎盘氨肽酶B对Cl-有显着活性。 Bestatin 和 Arphamenin（低分子量肽）对这种酶表现出明显的抑制作用。然而，amastatin 和purymycin 并不抑制该酶。杆菌肽显着激活了这种酶。
Aminopeptidase B (EC 3.4.11.6; L-arginyl-beta-naphthylamidase) was purified 1,800-fold from human placental cytoplasm and characterized. The enzyme was subjected to ammonium sulfate fractionation and a series of chromatographies on DE-52, hydroxylapatite, Bio-gel A 0.5 m and L-arginine-Sepharose. The native molecular mass of the enzyme was estimated to be 220,000 by gel filtration. The molecular mass was estimated to be about 83,000 by SDS/PAGE in the absence of 2-mercaptoethanol, suggesting that the enzyme exists in a polymeric form. The isoelectric point of the enzyme was 5.4. The purified enzyme was most active at pH 7.2 with L-arginyl-beta-naphthylamide as substrate and the K(m) value for this enzyme was 0.3 mmol/l. Human placental aminopeptidase B was markedly activity by Cl-. Bestatin and arphamenin, low molecular weight peptides, showed appreciable inhibition of this enzyme. However, amastatin and purymycin did not inhibit the enzyme. Bacitracin markedly activated this enzyme.