Becker E L, Ward P A
J Exp Med. 1969 Mar 1;129(3):569-84. doi: 10.1084/jem.129.3.569.
Previous published work has led to the hypothesis that the activatable esterase of chemotaxis is a serine esterase of the rabbit polymorphonuclear leukocyte existing in an inert, phosphonate insusceptible form, which after activation is capable of hydrolyzing aromatic amino acid esters and being inhibited by phosphonates. In the present study, directed to the testing of this hypothesis, we have shown that rabbit peritoneal polymorphonuclear leukocytes contain three esterases capable of hydrolyzing the aromatic amino acid ester, acetyl DL-phenylalanine beta-naphthyl ester. Two of these esterases, esterase 1 and esterase 2, are inhibited by various p-nitrophenyl ethyl phosphonate esters. The inhibition of each esterase is irreversible and progressive with time. When the logarithm of the esterase activity remaining after cell and inhibitor have been in contact for a constant time is plotted against the concentration of inhibitor, a straight line results. These results support the conclusion that both esterases are serine esterases. The third esterase, esterase 3, differs from the other two by its inability to be inactivated by any of the phosphonates no matter how high the concentration of phosphonate or prolonged the period of incubation of cell with phosphonate. The activity of esterase 1 is at least 10,000 times more easily inhibited by phosphonates than is that of esterase 2; incubating rabbit polymorphonuclear leukocytes for 15 min at 27 degrees C with 10(-9)-10(-8)M concentrations of various phosphonates inactivates esterase 1, but it required 10(-6)-10(-4)M concentrations of the same phosphonates to inhibit esterase 2. The inhibition profiles of esterase 1 are distinctly different from those of esterase 2 when the two esterases are tested with the phenylalkylphosphonates, chloroalkylphosphonates, and alkylphosphonates. The inhibition profile of esterase 1 is essentially the same as that of the activatable esterase of chemotaxis obtained previously when the same three homologous series of phosphonates were tested for their ability to protect against deactivation by the chemotactic factor or give chemotactic-dependent inhibition. It is tentatively concluded that esterase 1 of the rabbit peritoneal neutrophil is the activated form of the activatable esterase of chemotaxis.
趋化作用中可激活的酯酶是兔多形核白细胞中的一种丝氨酸酯酶，它以一种惰性的、对膦酸盐不敏感的形式存在，激活后能够水解芳香族氨基酸酯，并被膦酸盐抑制。在本研究中，为了验证这一假说，我们发现兔腹膜多形核白细胞含有三种能够水解芳香族氨基酸酯——乙酰 - DL - 苯丙氨酸β - 萘酯的酯酶。其中两种酯酶，酯酶1和酯酶2，可被各种对硝基苯乙基膦酸酯抑制。每种酯酶的抑制作用都是不可逆的，且随时间逐渐增强。当将细胞与抑制剂接触一定时间后剩余的酯酶活性的对数与抑制剂浓度作图时，得到一条直线。这些结果支持了这两种酯酶都是丝氨酸酯酶的结论。第三种酯酶，酯酶3，与其他两种不同，无论膦酸盐浓度多高或细胞与膦酸盐孵育时间多长，它都不会被任何膦酸盐灭活。酯酶1的活性比酯酶2更容易被膦酸盐抑制，至少相差10000倍；在27℃下，用10⁻⁹ - 10⁻⁸M浓度的各种膦酸盐孵育兔多形核白细胞15分钟可使酯酶1失活，但抑制酯酶2则需要10⁻⁶ - 10⁻⁴M浓度的相同膦酸盐。当用苯烷基膦酸盐、氯烷基膦酸盐和烷基膦酸盐对这两种酯酶进行测试时，酯酶1的抑制曲线与酯酶2明显不同。当用相同的三个同系物系列的膦酸盐测试其防止趋化因子失活或产生趋化依赖性抑制的能力时，酯酶1的抑制曲线与先前获得的趋化作用中可激活酯酶的抑制曲线基本相同。初步得出结论：兔腹膜中性粒细胞的酯酶1是趋化作用中可激活酯酶的激活形式。
