TUBULINYL-TYROSINE CARBOXYPEPTIDASE FROM CHICKEN BRAIN - PROPERTIES AND PARTIAL-PURIFICATION
TUBULINYL-TYROSINE CARBOXYPEPTIDASE FROM CHICKEN BRAIN - PROPERTIES AND PARTIAL-PURIFICATION
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DOI：
10.1111/j.1471-4159.1980.tb04628.x
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发表时间：
1980-01-01
影响因子：
4.7
通讯作者：
CAPUTTO, R
中科院分区：
文献类型：
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作者：
ARGARANA, CE;BARRA, HS;CAPUTTO, R
酪氨酸可以通过脑羧肽酶的作用从微管蛋白-酪氨酸中释放出来。通过Sephadex G-200柱凝胶过滤发现该酶的分子量为90，000。该酶在纯化的制剂中非常不稳定，其中每毫克蛋白质的活性相对于起始材料增加了250倍。由于待测材料中内源性微管蛋白酪氨酸的含量未知，因此无法说明纯化的精确程度。使用微管蛋白-[14 C]酪氨酸作为底物，对微管蛋白-酪氨酸羧肽酶（TTCP）活性和胰羧肽酶A（CPA，EC 3.4.12.2）活性进行了比较研究。发现的最显著的差异是：MgCl 2（2 mM）、乙酸苯酯（10 mM）或EDTA（5 mM）增加TTCP活性，而CPA活性被这些化合物强烈抑制，碘乙酸盐（2 mM）和ZnCl 2（0.1 mM）抑制TTCP活性超过CPA活性。相反，巯基乙醇（50 mM）和二甲基亚砜（5%）对CPA的抑制作用比对TTCP的抑制作用更强。在测试的几种N-苄氧羰基二肽（Z-二肽）中，对TTCP活性的最大抑制作用是用Z-Glu-Tyr和Z-Glu-Phe获得的，尽管对CPA的强抑制作用也是用其他Z-二肽获得的。
Tyrosine can be released from tubulinyl‐tyrosine by the action of a brain carboxypeptidase. The molecular weight of this enzyme found by gel filtration through a column of Sephadex G‐200 was 90,000. The enzyme was very unstable in a purified preparation in which the activity per milligram of protein was increased 250‐fold with respect to the starting material. The precise magnitude of the purification cannot be stated because of the unknown amount of endogenous tubulinyl‐tyrosine in the material to be assayed. A comparative study was done between tubulinyl‐tyrosine carboxypeptidase (TTCP) activity and pancreatic carboxypeptidase A (CPA, EC 3.4.12.2) activity using tubulinyl‐[14C]tyrosine as substrate. The most remarkable differences found are: MgCl2(2 mM), phenyl acetate (10 mM), or EDTA (5 mM) increased the TTCP activity whereas the CPA activity was strongly inhibited by these compounds, lodoacetate (2 mM) and ZnCl2(0.1 mM) inhibited the TTCP activity more than the CPA activity. Contrarily, mercaptoethanol (50 mM) and dimethyl sulfoxide (5%) showed a stronger inhibitory effect on CPA than on TTCP. Of several N‐carbobenzoxy dipeptides (Z‐dipeptides) tested the greatest inhibitory effects on TTCP activity were obtained with Z‐Glu‐Tyr and Z‐Glu‐Phe, although strong inhibitory effects on CPA were also obtained with other Z‐dipeptides.