Stadler P, Zandonella G, Haalck L, Spener F, Hermetter A, Paltauf F
Institut für Biochemie und Lebensmittelchemie, Technische Universität Graz, Spezialforschungsbereich Biokatalyse, Austria.
Biochim Biophys Acta. 1996 Dec 13;1304(3):229-44. doi: 10.1016/s0005-2760(96)00123-3.
1,2(2,3)-Diradylglycero O-(p-nitrophenyl) n-hexylphosphonates were synthesized, with the diradylglycerol moiety being di-O-octylglycerol, 1-O-hexadecyl-2-O-pyrenedecanylglycerol, or 1-O-octyl-2-oleoyl-glycerol, and tested for their ability to inactivate lipases from Chromobacterium viscosum (CVL) and Rhizopus oryzae (ROL). The experimental data indicate the formation of stable, covalent 1:1 enzyme-inhibitor adducts with the di-O-alkylglycero phosphonates. The differences in reactivity of diastereomeric phosphonates with opposite configuration at the glycerol backbone was less expressed with both enzymes tested as compared to the influence of the stereochemistry at the phosphorus. Both lipases exhibited the same preference for the chirality at the phosphorus that was independent from the absolute configuration at the glycerol backbone. However, with CVL and ROL the inhibitors with the active site serine-directed phosphonate linked at position sn-1 of the glycerol moiety reacted significantly faster than the corresponding sn-3 analogs, reflecting the sn-1 stereopreference of the enzymes towards triacylglycerol analogs with a sn-2 O-alkyl substituent. In contrast, the phosphonates based on the 1-O-octyl-2-oleoylglycerol did not significantly inactivate CVL. Unexpectedly, these substances were hydrolyzed in the presence of lipase.
合成了1,2(2,3)-二自由基甘油O-(对硝基苯基)正己基膦酸酯，其二自由基甘油部分为二-O-辛基甘油、1-O-十六烷基-2-O-芘癸基甘油或1-O-辛基-2-油酰基甘油，并测试了它们使粘质色杆菌（CVL）和米根霉（ROL）脂肪酶失活的能力。实验数据表明，二-O-烷基甘油膦酸酯与酶形成了稳定的共价1:1酶-抑制剂加合物。与磷原子上立体化学的影响相比，在甘油主链上具有相反构型的非对映体膦酸酯的反应性差异在两种测试酶中表现得较小。两种脂肪酶对磷原子上的手性表现出相同的偏好，这与甘油主链上的绝对构型无关。然而，对于CVL和ROL，在甘油部分sn-1位连接有活性位点丝氨酸导向膦酸酯的抑制剂比相应的sn-3类似物反应明显更快，这反映了酶对具有sn-2 O-烷基取代基的三酰甘油类似物的sn-1立体选择性。相比之下，基于1-O-辛基-2-油酰基甘油的膦酸酯不会使CVL显著失活。出乎意料的是，这些物质在脂肪酶存在下会被水解。
