Hernell O, Olivecrona T
J Lipid Res. 1974 Jul;15(4):367-74.
Lipase activity has previously been demonstrated in human milk. This study shows that there are two separate triglyceride lipases in human milk. One is mainly in the skim milk and is stimulated by bile salts; the other is mainly in the cream and is inhibited by bile salts but stimulated by serum. The serum-stimulated lipase was purified by affinity chromatography on heparin-substituted Sepharose 4B. This gave a 9500-fold purification over whole milk. Although polyacrylamide gel electrophoresis showed that the enzyme was not purified to homogeneity, it had the highest specific activity so far reported for a human serum-stimulated lipase. The purified enzyme was free from bile salt-stimulated lipase activity and had the characteristics of other serum-stimulated or so-called lipoprotein lipases. Thus, it was almost completely inhibited by 1 M NaCl. The purified enzyme was active against tributyrylglycerol also in the absence of exogenous serum factors.
此前已证实在人乳中存在脂肪酶活性。本研究表明，人乳中存在两种不同的甘油三酯脂肪酶。一种主要存在于脱脂乳中，受胆盐刺激；另一种主要存在于乳脂中，受胆盐抑制但受血清刺激。通过在肝素取代的琼脂糖4B上进行亲和层析纯化了受血清刺激的脂肪酶。与全脂乳相比，纯化倍数达到9500倍。尽管聚丙烯酰胺凝胶电泳显示该酶未纯化至均一，但它具有迄今为止报道的人血清刺激脂肪酶的最高比活性。纯化后的酶无胆盐刺激脂肪酶活性，具有其他血清刺激或所谓脂蛋白脂肪酶的特性。因此，它几乎完全被1M氯化钠抑制。纯化后的酶在无外源性血清因子的情况下对三丁酰甘油也有活性。
