The Effects of Salts and of Ionic Strength on the Hydrolysis of TAME (p-toluenesulfonyl-L-arginine methyl ester) by Thrombin and Thrombokinase
The Effects of Salts and of Ionic Strength on the Hydrolysis of TAME (p-toluenesulfonyl-L-arginine methyl ester) by Thrombin and Thrombokinase
复制标题
盐和离子强度对凝血酶和血栓激酶水解TAME（对甲苯磺酰基-L-精氨酸甲酯）的影响
DOI：
10.1055/s-0038-1649397
复制
发表时间：
1972
影响因子：
6.7
通讯作者：
P. B. Fleming
中科院分区：
文献类型：
--
作者：
P. S. Roberts;P. B. Fleming
总结不同浓度的碱金属氯化物的影响（LiCl、NaCl、KCl、RbCl和CsCl）、碱土金属氯化物（BeCl 2、MgCl 2、CaCl 2、SrCl 2和BaCl 2）、氯化胆碱和Tris、HCl（pH8.0，37°）对人凝血酶和牛凝血酶激酶的纯化制剂水解驯服的速率的影响，pH 8.0，37°。每种盐对反应都有其各自的影响，当使用凝血酶代替凝血酶激酶时，这些影响完全不同。然而，每一种盐，有相同的质量效果驯服水解粗牛凝血酶由纯化的人凝血酶，但只有轻微的影响驯服的水解胰蛋白酶。除氯化锂外，低浓度的碱金属氯化物对凝血酶-TAME和凝血酶激酶-TAME反应均有抑制作用，高浓度则有加速作用。氯化锂对上述两种反应均无加速作用，是一种比凝血酶更强的凝血酶激酶抑制剂。与碱金属氯化物相比，碱土金属氯化物对这两个反应都没有促进作用，但有抑制作用。但MgCl 2是个例外。对凝血酶-驯服反应有微弱的促进作用，对凝血酶-驯服反应有微弱的抑制作用.当比较0.15M浓度的盐时（除了BeCl 2，它是两种反应的最强抑制剂），NaCl是凝血酶-驯服反应的最强抑制剂，其次是CaCl 2，但BaCl 2是凝血酶激酶-驯服反应的最强抑制剂，其次是KCl和LiCl。氯化胆碱和Tris.HCl浓度高达3 M时，对人或牛凝血酶水解驯服的速率没有显著影响。因此，将离子强度增加到0.16以上（未测试较低值）可能对该反应没有影响，并且在碱金属氯化物或碱土金属氯化物存在下发现的所有抑制和加速可能完全是由于单个阳离子。另一方面，增加离子强度可产生小的抑制作用，如在LiCl或MgCl 2存在下所发现的，并且在甚至大浓度的Tris·HCl或氯化胆碱存在下缺乏任何作用可能是由于胆碱和Tris阳离子的弱加速作用偶然平衡了离子强度的弱抑制作用。氯化胆碱和盐酸三羟甲基氨基甲烷对凝血酶-TAME反应无抑制作用，但可加速凝血酶-TAME反应.氯化胆碱是测试过的最强的促进剂。在0.15和3 M氯化胆碱存在下的速率分别为对照的204和601%。虽然离子强度变化对该反应的影响无法确定，但数据表明，增加离子强度至多只有很小的影响，并且发现的抑制和加速主要是由于存在的特定阳离子。
Summary The effects of varying concentrations of alkali chlorides (LiCl, NaCl, KC1, RbCl and CsCl), alkaline earth chlorides (BeCl2, MgCl2, CaCl2, SrCl2, and BaCl2), choline chloride and Tris,HCl (pH 8.0 at 37°) on the rates of hydrolysis of TAME by a purified preparation of human thrombin and of bovine thrombokinase were determined in 0.25 M Tris.HCl buffer, pH 8.0 at 37°. Each salt had its own individual effects on the reactions and these effects were completely different when thrombin instead of thrombokinase was used. Each salt, however, had the same qualitative effects on TAME hydrolysis by crude bovine thrombin as by purified human thrombin, but only minor effects on the hydrolysis of TAME by trypsin. With the exception of LiCl, low concentrations of alkali chlorides had inhibitory and high concentrations had acceleratory effects on both the thrombin-TAME and the thrombokinase-TAME reactions. LiCl had no accelerating effects on either reaction and it was a stronger inhibitor of thrombokinase than of thrombin. In contrast to the alkali chlorides, the alkaline earth chlorides had no acceleratory effects but had inhibitory effects on both reactions. MgCl2, however, was an exception. It weakly accelerated the thrombokinase -TAME and weakly inhibited the thrombin -TAME reaction. When comparing 0.15 M concentrations of the salts (with the exception of BeCl2 which was the strongest inhibitor of both reactions), NaCl was the strongest inhibitor of the thrombin - TAME reaction, followed by CaCl2, but BaCl2 was the strongest inhibitor of the thrombokinase -TAME reaction, followed by KC1 and LiCl. Choline chloride and Tris.HCl in concentrations up to 3 M had no significant effects on the rate of hydrolysis of TAME by either human or bovine thrombin. Increasing the ionic strength above 0.16 (lower values were not tested), therefore, may have no effect on this reaction, and all of the inhibitions and accelerations found in the presence of the alkali chlorides or the alkaline earth chlorides may be entirely due to the individual cations. On the other hand, increasing the ionic strength may produce a small inhibitory effect, as found in the presence of LiCl or MgCl2, and the lack of any effect in presence of even large concentrations of Tris.HCl or choline chloride may be due to a fortuitous balancing of the weak inhibitory effect of ionic strength by the weak acceleratory effect of the choline and Tris cations. Choline chloride and Tris.HCl had no inhibitory effects but accelerated the thrombokinase -TAME reaction. Choline chloride was the strongest accelerator tested. Rates in the presence of 0.15 and 3 M choline chloride were respectively 204 and 601 % of the controls. Although the effects of ionic strength changes on this reaction could not be established, the data indicate that increasing the ionic strength has at most only a small effect, and the inhibitions and accelerations found are due primarily to the specific cations present.