Gargouri Y, Pieroni G, Riviere C, Sauniere J F, Lowe P A, Sarda L, Verger R
Gastroenterology. 1986 Oct;91(4):919-25. doi: 10.1016/0016-5085(86)90695-5.
Under optimal conditions, assay for pure human gastric lipase was carried out with short- and long-chain triacylglycerol emulsions. Maximal specific activities of 1160 and 620 U/mg were obtained with tributyrin and soybean emulsion, respectively. We observed that with a tributyrin substrate, bovine serum albumin or bile salts must be added before the addition of the enzyme in order to prevent its irreversible interfacial denaturation. With long-chain triacylglycerols as substrate, a decrease with time in the rate of hydrolysis was associated with release of protonated long-chain fatty acids. The inhibitory effect of protonated fatty acids was also observed using tributyrin at pH 3.0. These observations support the conclusion that human gastric lipase shows no intrinsic specificity for short-chain triacylglycerols and that its apparent specificity is modulated by pH and presence of amphiphile in the incubation medium. Our conclusions support the view that, in the human, gastric lipolysis may play an important role in long-chain fat digestion.
在最佳条件下，使用短链和长链三酰甘油乳剂对纯人胃脂肪酶进行了测定。分别用丁酸甘油酯和大豆乳剂获得了1160和620 U/mg的最大比活性。我们观察到，对于丁酸甘油酯底物，在添加酶之前必须先添加牛血清白蛋白或胆汁盐，以防止其不可逆的界面变性。以长链三酰甘油为底物时，水解速率随时间的降低与质子化长链脂肪酸的释放有关。在pH 3.0条件下使用丁酸甘油酯时也观察到了质子化脂肪酸的抑制作用。这些观察结果支持以下结论：人胃脂肪酶对短链三酰甘油没有内在特异性，其表观特异性受pH值和孵育介质中两亲分子的存在调节。我们的结论支持这样一种观点，即在人类中，胃脂肪分解在长链脂肪消化中可能起重要作用。
