TRYPTIC CLEAVAGE OF HOMOARGINYL BONDS IN OXIDIZED GUANIDINATED DERIVATIVE OF A BOVINE TRYPSIN INHIBITOR (KUNITZ INHIBITOR)
TRYPTIC CLEAVAGE OF HOMOARGINYL BONDS IN OXIDIZED GUANIDINATED DERIVATIVE OF A BOVINE TRYPSIN INHIBITOR (KUNITZ INHIBITOR)
复制标题
DOI：
10.1016/0014-5793(71)80460-x
复制
发表时间：
1971-01-01
期刊：
影响因子：
3.5
通讯作者：
ACHER, R
中科院分区：
文献类型：
--
作者：
CHAUVET, J;ACHER, R
最近关于一些涉及高精氨酸 [I] 的肽键被胰蛋白酶裂解的报告促使我们发表在对从牛肉组织中分离的 Kunitz 胰蛋白酶抑制剂的胍基衍生物进行研究期间观察到的结果。该分子由 58 个残基的单条多肽链组成，其中 4 个是赖氨酸。可以研究导致不符合胰蛋白酶特异性的衍生物的单个赖氨酸的化学修饰，因为赖氨酸在序列中与精氨酸交替，并且可以在胰蛋白酶水解后分离出含有单个赖氨酰残基的重叠肽 [2, 3] 胍基化已用于确定抑制剂的 01. 和 e-氨基在与胰蛋白酶相互作用中各自的作用；据观察，在所述条件[4]下，3.87个赖氨酰残基转化为高精氨酰残基（胍化产率：97%），并且α-氨基显然没有被修饰。胍基抑制剂具有完全活性 [4, 51 但氧化会破坏其抑制能力。进行过甲酸氧化、胰蛋白酶水解（酶/底物摩尔比l/250；pH 8.0；60分钟；37’）以及通过肽图谱分离肽。如前所述 [6, 7]。图1显示了氧化型胍基抑制剂的胰蛋白酶肽图。对肽进行分析 [8] 并根据其组成进行鉴定（表 I），从而可以定位胰蛋白酶裂解的键。假设精氨酰键完全断裂（在氧化抑制剂的胰蛋白酶消化中观察到的条件），并使用肽 T3 和 Tg 作为参考，大约确定了 4 个高精氨酰键的裂解产率。
The recent report of tryptic cleavage of some peptide bonds involving homoarginine [I] prompts us to publish results observed during a study on the guanidinated derivative of the Kunitz trypsin inhibitor isolated from beef tissues. The molecule is comprised of a single polypeptide chain of 58 residues, 4 of which are lysines. Chemical modifications of individual lysines leading to derivatives which do not fit the specificity of trypsin can be studied because lysines alternate with arginines in the sequence and overlapping peptides containing a single lysyl residue can be isolated after tryptic hydrolysis [2, 3] Guanidination has been employed to determine the respective roles of the 01. and e-amino groups of the inhibitor in the interaction with trypsin; it was observed that under the described conditions [4], 3.87 lysyl residues were converted into homoarginyl residues (yield of the guanidination: 97%) and that the a-amino group is apparently not modified. The guanidinated inhibitor is fully active [4, 51 but oxidation destroys the inhibiting capacity. Performic acid oxidation, tryptic hydrolysis (molar ratio enzyme/substrate l/250; pH 8.0; 60 min; 37’) and isolation of peptides by peptide mapping were carried. out as previously described [6, 7]. Fig. 1 shows the tryptic peptide map of the oxidized guanidinated inhibitor. The peptides were analyzed [8] and identified from their composition (table I), allowing to locate the bonds split by trypsin. The yields of cleavage at the 4 homoarginyl bonds were approximately determined assuming complete splitting of arginyl bonds, a condition observed in the trypsin digest of the oxidized inhibitor [6, 7], and using peptides T3 and Tg as references.