Nagai Y, Oka H
Gastroenterol Jpn. 1985 Feb;20(1):53-64. doi: 10.1007/BF02774674.
Prolyl hydroxylase was purified from human placentae, specific antiserum against it was prepared, and a new radioimmunoassay system employing 125I-labelled enzyme preparation was established. The molecular weight of the placental enzyme was shown to be 320,000 by gel filtration. SDS-polyacrylamide gel electrophoresis showed two bands of unequal intensity having molecular weights of 60,000 and 130,000. Their amino acid compositions were identical to each other, suggesting the polypeptide with a molecular weight of 130,000 might be a dimer of the polypeptide with a molecular weight of 60,000. The new radioimmunoassay established had a sensitivity of the order of 10 ng/ml, indicating it was more sensitive than previous radioimmunoassay employing 3H-labelling method. Clinical studies on patients with liver diseases disclosed that the concentrations of serum immunoreactive prolyl hydroxylase were elevated both in cases of hepatocellular damage and in cases of cholestasis. In cases of hepatocellular damage the enzyme behaved like cytoplasmic enzymes such as glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and lactic dehydrogenase, but in cases of cholestasis it resembled biliary enzymes such as alkaline phosphatase and gamma-glutamyl transpeptidase. This result might be associated with the peculiar location of the enzyme within the cell, in the membrane of rough endoplasmic reticulum.
从人胎盘中纯化出脯氨酰羟化酶，制备了针对该酶的特异性抗血清，并建立了一种采用125I标记酶制剂的新型放射免疫分析系统。通过凝胶过滤法测得胎盘酶的分子量为320,000。SDS-聚丙烯酰胺凝胶电泳显示出两条强度不等的条带，分子量分别为60,000和130,000。它们的氨基酸组成彼此相同，这表明分子量为130,000的多肽可能是分子量为60,000的多肽的二聚体。所建立的新型放射免疫分析的灵敏度约为10 ng/ml，表明它比以前采用3H标记法的放射免疫分析更灵敏。对肝病患者的临床研究表明，在肝细胞损伤和胆汁淤积的病例中，血清免疫反应性脯氨酰羟化酶的浓度均升高。在肝细胞损伤的病例中，该酶的表现类似于细胞质酶，如谷草转氨酶、谷丙转氨酶和乳酸脱氢酶，但在胆汁淤积的病例中，它类似于胆汁酶，如碱性磷酸酶和γ-谷氨酰转肽酶。这一结果可能与该酶在细胞内粗面内质网膜中的特殊定位有关。
