Reddy G L, Nagaraj R
Biochim Biophys Acta. 1985 Oct 18;831(3):340-6. doi: 10.1016/0167-4838(85)90117-7.
Circular dichroism studies on synthetic peptides corresponding to the signal sequences of chicken lysozyme and Escherichia coli proteins, lambda-receptor and lipoprotein, have been carried out in trifluoroethanol. The peptides, (CH3)3-C-O-CO-Thr-Leu-Lys-Lys-Leu-Pro-Leu-Ala-Val-Ala-Val-Ala-Ala-Gly- Val-Met-Thr-Ala- Ala-Met-Ala-OCH3, (CH3)3-C-O-CO-Met-Lys-Ser-Leu-Leu-Ile-Leu-Val-Leu-Cys(benzyl)- Phe-Leu-Pro- Leu-Ala-Ala-Leu-Gly-OH and (CH3)3-C-O-CO-Leu-Val-Leu-Gly-Ala-Val-Ile-Leu-Gly- Thr-Thr-Leu-Leu- Ala-Gly-OCH3, corresponding to the signal sequences of lambda-receptor, lysozyme and the hydrophobic region of lipoprotein, respectively, show two negative bands at approx. 205 and 220 nm, characteristic of an alpha-helical conformation. Secondary structural features are discernible even in the shorter, 12-residue carboxy-terminal fragments of these signal peptides. A comparison of the conformation of the amino-terminal, central and carboxy-terminal fragments of lipoprotein signal sequence indicates that the central octapeptide fragment is more structurally ordered compared to the amino- and carboxy-terminal fragments.
已在三氟乙醇中对与鸡溶菌酶、大肠杆菌蛋白、λ受体和脂蛋白信号序列相对应的合成肽进行了圆二色性研究。这些肽分别为(CH3)3-C-O-CO-Thr-Leu-Lys-Lys-Leu-Pro-Leu-Ala-Val-Ala-Val-Ala-Ala-Gly-Val-Met-Thr-Ala-Ala-Met-Ala-OCH3、(CH3)3-C-O-CO-Met-Lys-Ser-Leu-Leu-Ile-Leu-Val-Leu-Cys(苄基)-Phe-Leu-Pro-Leu-Ala-Ala-Leu-Gly-OH和(CH3)3-C-O-CO-Leu-Val-Leu-Gly-Ala-Val-Ile-Leu-Gly-Thr-Thr-Leu-Leu-Ala-Gly-OCH3，它们分别对应于λ受体、溶菌酶的信号序列以及脂蛋白的疏水区域，在约205和220nm处显示出两个负带，这是α-螺旋构象的特征。即使在这些信号肽较短的12个残基的羧基末端片段中，二级结构特征也清晰可辨。对脂蛋白信号序列的氨基末端、中央和羧基末端片段的构象比较表明，与氨基末端和羧基末端片段相比，中央八肽片段的结构更有序。
