Shock A, Baum H, Kapasi M F, Bull F M, Quinn P J
Biochemistry Department, Kings' College University of London, UK.
Matrix. 1990 Jul;10(3):179-85. doi: 10.1016/s0934-8832(11)80167-8.
Elastin in vivo is likely to be complexed with amphipathic ligands such as lipids. The susceptibility of stable [3H] elastin-fatty acid complexes to the action of porcine pancreatic elastase (PPE) and to human neutrophil lysates over time was assessed. Elastolysis by PPE of substrates prepared with oleic or linoleic acids was initially higher (for up to 2 hours) than that of uncomplexed elastin. Stearic acid and elaidic acid (the trans isomer of oleic acid) did not enhance the elastolytic rate above control. The stimulatory effect of oleic and linoleic acids appeared to derive from increased adsorption of PPE onto elastin; the loss of stimulatory activity over time occurred in parallel with a progressive decrease in adsorption. All fatty acids tested inhibited elastolysis by neutrophil lysates, the effect being particularly marked with oleic and elaidic acids. These results indicate that 1). Complexed fatty acids can modulate the rate of elastin breakdown by elastases; 2). The effects observed with PPE are due to differences in adsorption of enzyme onto substrate, possibly as a result of steric considerations; 3). Since elastolysis by neutrophil lysates is inhibited by all fatty acids, the properties of different elastolytic enzymes should be considered in in vitro model systems of connective tissue breakdown.
体内的弹性蛋白可能与两亲性配体如脂质复合。评估了稳定的[3H]弹性蛋白 - 脂肪酸复合物随时间对猪胰弹性蛋白酶（PPE）和人中性粒细胞裂解物作用的敏感性。用油酸或亚油酸制备的底物经PPE的弹性蛋白水解作用最初（长达2小时）高于未复合的弹性蛋白。硬脂酸和反油酸（油酸的反式异构体）并未使弹性蛋白水解速率高于对照。油酸和亚油酸的刺激作用似乎源于PPE在弹性蛋白上吸附的增加；刺激活性随时间的丧失与吸附的逐渐减少同时发生。所有测试的脂肪酸均抑制中性粒细胞裂解物的弹性蛋白水解作用，油酸和反油酸的作用尤为明显。这些结果表明：1）复合脂肪酸可调节弹性蛋白酶对弹性蛋白的降解速率；2）PPE观察到的效应是由于酶在底物上吸附的差异，可能是由于空间因素；3）由于所有脂肪酸均抑制中性粒细胞裂解物的弹性蛋白水解作用，因此在结缔组织分解的体外模型系统中应考虑不同弹性蛋白酶的特性。
