Aoubala M, Bonicel J, Bénicourt C, Verger R, De Caro A
UPR 9025 "Lipolyse Enzymatique" du Centre National de la Recherche Scientifique, Marseille, France.
Biochim Biophys Acta. 1994 Aug 4;1213(3):319-24. doi: 10.1016/0005-2760(94)00058-1.
Human (HGL) and rabbit (RGL) gastric lipases were cleaved by trypsin and the resulting peptides were characterized. Exposure of HGL to trypsin led to the production of three identified fragments (H1, H2 and H3) resulting from cleavage sites at Lys-4 and Arg-229. Fragments H2 (Lys-4-Arg-229) and H3 (Glu-230-Lys-379) were derived from fragment H1 (Lys-4-Lys-379). The single disulfide bridge (Cys-236-Cys-244) of the molecule is localized in fragment H3. Out of the three cysteine residues conserved in all known gastric lipases, the free sulfhydryl group (Cys-227) was localized in fragment H2. Immunoblots, carried out with the tryptic fragments of HGL and anti-HGL mAbs, revealed that five inhibitory mAbs immunoreacted selectively with the N-terminal fragment H2, whereas two other non inhibitory mAbs immunoreacted exclusively with the C-terminal fragment H3. Trypsin also cleaved RGL at two sites (Arg-55 and Arg-229) leading to four identifiable fragments (R1, R2, R3 and R4). One cleavage site (Arg-229) was found to be identical in both RGL and HGL. We propose that this latter site is localized between the two domains of native gastric lipases.
人源（HGL）和兔源（RGL）胃脂肪酶用胰蛋白酶进行切割，并对产生的肽段进行表征。将HGL暴露于胰蛋白酶导致产生三个已鉴定的片段（H1、H2和H3），这是由赖氨酸-4和精氨酸-229处的切割位点产生的。片段H2（赖氨酸-4-精氨酸-229）和H3（谷氨酸-230-赖氨酸-379）源自片段H1（赖氨酸-4-赖氨酸-379）。该分子的单个二硫键（半胱氨酸-236-半胱氨酸-244）位于片段H3中。在所有已知胃脂肪酶中保守的三个半胱氨酸残基中，游离巯基（半胱氨酸-227）位于片段H2中。用HGL的胰蛋白酶片段和抗HGL单克隆抗体进行的免疫印迹显示，五种抑制性单克隆抗体与N端片段H2选择性反应，而另外两种非抑制性单克隆抗体仅与C端片段H3反应。胰蛋白酶还在两个位点（精氨酸-55和精氨酸-229）切割RGL，产生四个可识别的片段（R1、R2、R3和R4）。发现RGL和HGL中有一个切割位点（精氨酸-229）是相同的。我们认为后一个位点位于天然胃脂肪酶的两个结构域之间。
