A Heme-binding Aspartic Proteinase from the Eggs of the Hard TickBoophilus microplus *
A Heme-binding Aspartic Proteinase from the Eggs of the Hard TickBoophilus microplus *
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来自微小牛蜱卵的血红素结合天冬氨酸蛋白酶*
DOI：
--
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发表时间：
2000
影响因子：
4.8
通讯作者：
P. Oliveira
中科院分区：
文献类型：
--
作者：
M. Sorgine;C. Logullo;R. Zingali;G. O. Paiva;L. Juliano;P. Oliveira
从牛蜱（boophilus microplus）卵中分离并克隆了一种与血红素结合的天冬氨酸蛋白酶，其化学计量比为1:1。这种被命名为THAP（蜱血红素结合天冬氨酸蛋白酶）的蛋白酶对几种肽和蛋白质底物表现出胃抑素敏感的水解活性。虽然血红蛋白是THAP的良好底物，但对缺乏血红素假基的球蛋白的蛋白水解活性较低。随着血红素添加量的增加，THAP对珠蛋白的水解作用也随之增加，当血红素与珠蛋白的比例为1:1时，THAP的活化作用最大。在反应培养基中进一步添加血红素抑制蛋白水解，使其恢复到与单独对珠蛋白观察到的水平相似。添加血红素不会改变THAP对合成肽或对非血红蛋白底物核糖核酸酶的活性。蜱卵的主要储存蛋白，卵黄蛋白（VT），可能是THAP的生理底物，是一种血红蛋白。在培养液中加入血红素也能抑制THAP对VT的水解。综上所述，我们的研究结果表明THAP利用与VT结合的血红素作为对接位点，根据血红素的可用性来增加特异性并调节VT降解。
An aspartic proteinase that binds heme with a 1:1 stoichiometry was isolated and cloned from the eggs of the cattle tickBoophilus microplus. This proteinase, herein named THAP (tick heme-binding aspartic proteinase) showed pepstatin-sensitive hydrolytic activity against several peptide and protein substrates. Although hemoglobin was a good substrate for THAP, low proteolytic activity was observed against globin devoid of the heme prosthetic group. Hydrolysis of globin by THAP increased as increasing amounts of heme were added to globin, with maximum activation at a heme-to-globin 1:1 ratio. Further additions of heme to the reaction medium inhibited proteolysis, back to a level similar to that observed against globin alone. The addition of heme did not change THAP activity toward a synthetic peptide or against ribonuclease, a non-hemeprotein substrate. The major storage protein of tick eggs, vitellin (VT), the probable physiological substrate of THAP, is a hemeprotein. Hydrolysis of VT by THAP was also inhibited by the addition of heme to the incubation media. Taken together, our results suggest that THAP uses heme bound to VT as a docking site to increase specificity and regulate VT degradation according to heme availability.
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DOI：
10.1016/s0021-9258(18)61070-1
发表时间：
1987-07
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
P. Matsudaira
通讯作者：
P. Matsudaira
大鼠体内 Z 类肝胞质蛋白的蛋白质，优先结合血红素。
DOI：
--
发表时间：
1985
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Vincent,SH;Muller-Eberhard,U
通讯作者：
Muller-Eberhard,U
纤维蛋白原-琼脂糖与凝血酶原、凝血酶前 1、凝血酶前 2 和凝血酶的相互作用。
DOI：
10.1016/0167-4838(87)90286-x
发表时间：
1987
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Kaczmarek,E;Kaminski,M;McDonagh,J
通讯作者：
McDonagh,J
DOI：
10.1073/pnas.88.2.325
发表时间：
1991-01-01
影响因子：
11.1
作者：
SLATER, AFG;SWIGGARD, WJ;HENDERSON, GB
通讯作者：
HENDERSON, GB
影响因子：
4.1
作者：
GUTTERIDGE, JMC;SMITH, A
通讯作者：
SMITH, A