期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 138, 期 8, 页码 2849-2857出版社
AMER CHEMICAL SOC
DOI: 10.1021/jacs.6b00093
关键词
-
资金
- NSF CRIF Instrumentation Development [CHE-0820766]
- NSF [CHE-1213289, CHE-1465028]
- DOE [FG02-00ER15105]
- Division Of Chemistry
- Direct For Mathematical & Physical Scien [1465028] Funding Source: National Science Foundation
- Division Of Chemistry
- Direct For Mathematical & Physical Scien [1213289] Funding Source: National Science Foundation
Ultraviolet and infrared-ultraviolet (IR-UV) double-resonance photofragment spectroscopy has been carried out in a tandem mass spectrometer to determine the three-dimensional structure of cryogenically cooled protonated C-terminally methyl esterified leucine enkephalin [YGGFL-OMe+H](+). By comparing the experimental IR spectrum of the dominant conformer with the predictions of DFT M05-2X/6-31+G(d) calculations, a backbone structure was assigned that is analogous to that previously assigned by our group for the unmodified peptide [Burke, N.L.; et al. Int. J. Mass Spectrom. 2015, 378, 196], despite the loss of a C-terminal OH binding site that was thought to play an important role in its stabilization. Both structures are characterized by a type II' beta-turn around Gly(3)-Phe(4) and a gamma-turn around Gly(2), providing spectroscopic evidence for the formation of a beta-hairpin hydrogen bonding pattern. Rather than disrupting the peptide backbone structure, the protonated N-terminus serves to stabilize the beta-hairpin by positioning itself in a pocket above the turn where it can form H-bonds to the Gly(3) and C-terminus C=0 groups. This beta-hairpin type structure has been previously proposed as the biologically active conformation of leucine enkephalin and its methyl ester in the nonpolar cell membrane environment [Naito, A.; Nishimura, K. Curr. Top. Med. Chem. 2004, 4, 135-143].
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据