Adams E, Lamon M
J Biol Chem. 1977 Nov 10;252(21):7591-7.
A relatively crude enzyme preparation derived from the subcuticular epithelium of earthworms catalyzed the formation of 4-hydroxyproline from prolyl residues in unhydroxylated natural collagens and in several synthetic collagen-like polypeptides. The specificity of hydroxylation differed from that of all vertebrate polyl hydroxylases in that (Gly-Pro-Ala)n was a much better substrate than (Gly-Ala-Pro)n. In contrast, however, only the so-called Y position proline (Gly-X-Y) was hydroxylated in Gly-Pro-Pro sequences derived either from natural collagen or from synthetic polypeptides; specificity of hydroxylation for the latter sequence is identical with that of the vertebrate enzymes. Little or no formation of 3-hydroxyproline could be demonstrated in preparations of the enzyme active as a 4-hydroxylase. In contrast with an earlier report from another laboratory, using a crude extract of earthworm body wall, we were unable to demonstrate either significant 3-hydroxyproline formation or efficient 4-hydroxylation of X position prolyl residues in synthetic polypeptides with the internal sequence Gly-Pro-Pro.
一种从蚯蚓皮下上皮提取的相对粗制的酶制剂，能催化未羟基化的天然胶原蛋白和几种合成类胶原多肽中的脯氨酰残基形成4-羟基脯氨酸。羟基化的特异性与所有脊椎动物的多羟基化酶不同，因为（甘氨酸-脯氨酸-丙氨酸）n 是比（甘氨酸-丙氨酸-脯氨酸）n 更好的底物。然而，相比之下，无论是天然胶原蛋白还是合成多肽来源的甘氨酸-脯氨酸-脯氨酸序列中，只有所谓的Y位脯氨酸（甘氨酸-X-Y）被羟基化；后者序列的羟基化特异性与脊椎动物酶相同。在作为4-羟化酶具有活性的酶制剂中，几乎没有或无法证明有3-羟基脯氨酸的形成。与另一个实验室使用蚯蚓体壁粗提物的早期报告相反，我们无法证明在具有内部序列甘氨酸-脯氨酸-脯氨酸的合成多肽中有显著的3-羟基脯氨酸形成或X位脯氨酰残基的有效4-羟基化。
