We recently reported that C-terminal polyamine modification occurs when proteins are digested with trypsin in the presence of polyamine [Biochem. Biophys. Res. Commun., 356, 159—162 (2007)]. In the present study, the characteristics of this C-terminal modification in the presence of protease and amine were investigated. When hemoglobin (HB) was digested with trypsin in the presence of N-(2-pyridyl)-1,4-diaminobutane (Py4), formation of the modified peptide was dependent on time and on HB or Py4 concentration. When synthetic peptide was treated with trypsin in the presence of Py4, ca. 0.1% of the peptide was modified with Py4. When HB or cytochrome C was treated with a range of serine proteases in the presence of various amines (Py4, N-(2-pyridyl)-1,3-diaminopropane, tranexamic acid, isonicotinic acid hydrazide and ampicillin), the modified peptide was detected in all cases tested, thus suggesting that amine modification widely accompanies digestion by proteases.
我们最近报告了在存在
多胺的情况下,蛋白质在胰
蛋白酶消化时会发生C末端
多胺修饰[
生物化学与
生物物理研究通讯,356,159—162(2007)]。在本研究中,探讨了在存在
蛋白酶和胺时这种C末端修饰的特征。当将血红蛋白(HB)与胰
蛋白酶在存在N-(2-
吡啶基)-1,4-二
氨基
丁烷(Py4)的情况下消化时,修饰肽的形成依赖于时间和HB或Py4的浓度。当合成肽在Py4存在的情况下与胰
蛋白酶处理时,约0.1%的肽被Py4修饰。当HB或
细胞色素C在多种胺(Py4,N-(2-
吡啶基)-1,3-二
氨基
丙烷,
氨甲
环酸,
异烟酸肼和
青霉素)存在的情况下与一系列
丝氨酸蛋白酶处理时,在所有测试的情况下均检测到修饰肽,这表明胺修饰广泛伴随
蛋白酶的消化。