Forood B, Feliciano E J, Nambiar K P
Department of Chemistry, University of California, Davis 95616.
Proc Natl Acad Sci U S A. 1993 Feb 1;90(3):838-42. doi: 10.1073/pnas.90.3.838.
The alpha-helix-stabilizing effect of different amino acid residues at the helical termini of short peptides in aqueous solution has been determined. Several dodecapeptides containing alanine, asparagine, aspartate, glutamine, glutamate, and serine at the amino terminus and arginine, lysine, and alanine at the carboxyl terminus were synthesized, and the alpha-helical content of each peptide was measured by using circular dichroism spectroscopy. The trend in alpha-helix-inducing ability of these amino acids was found to be as follows: aspartate > asparagine > serine > glutamate > glutamine > alanine at the amino terminus and arginine > lysine > alanine at the carboxyl terminus. Our results agree with the Presta and Rose hypothesis [Presta, L. G. & Rose, G. D. (1988) Science 240, 1632-1641] on the role of end capping in helix stabilization.
已测定了水溶液中短肽螺旋末端不同氨基酸残基的α-螺旋稳定作用。合成了几种在氨基末端含有丙氨酸、天冬酰胺、天冬氨酸、谷氨酰胺、谷氨酸和丝氨酸,在羧基末端含有精氨酸、赖氨酸和丙氨酸的十二肽,并使用圆二色光谱法测量了每种肽的α-螺旋含量。发现这些氨基酸诱导α-螺旋的能力趋势如下:氨基末端为天冬氨酸>天冬酰胺>丝氨酸>谷氨酸>谷氨酰胺>丙氨酸,羧基末端为精氨酸>赖氨酸>丙氨酸。我们的结果与Presta和Rose关于封端在螺旋稳定中作用的假设[Presta, L. G. & Rose, G. D. (1988) Science 240, 1632 - 1641]一致。