✦ LIBER ✦

The effect of N-methylation on helical peptides

✍ Scribed by Chi-Fon Chang; Micheal H. Zehfus

Publisher: Wiley (John Wiley & Sons)
Year: 1998
Tongue: English
Weight: 632 KB
Volume: 40
Category: Article
ISSN: 0006-3525
DOI: 10.1002/(sici)1097-0282(1996)40:6<609::aid-bip2>3.0.co;2-#

No coin nor oath required. For personal study only.

✦ Synopsis

In N-methyl amino acids, the hydrogen of the N-H group is replaced with a bulky methyl group. While this change is expected to destabilize helical structures, the amount of destabilization is not known. Here the N-methyl group is placed into several positions of the helical peptides, acetyl-WGG( EAAAR jrA-amide and acetyl-WGG(RAAAA j4R-amide, and the melting of the peptides followed using CD.

When analyzed using a simple two-state model, the destabilization associated with the H to CH, substitution at 0°C is between 0.3 to 1.7 kcalhole and is position dependent. The melting data may also be analyzed using a modi$ed form of the Lifson-Roig statistics that should more correctly model the helix-coil transition in this small peptide. This analysis fails, however, apparently because the destabilization energy is greater than the energy that can be attributed to a single residue in this model.

📜 SIMILAR VOLUMES

IR spectroscopy of isotope-labeled helic

IR spectroscopy of isotope-labeled helical peptides: Probing the effect of N-acetylation on helix stability

✍ Sean M. Decatur 📂 Article 📅 2000 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 139 KB 👁 1 views

Effect of O(2′)-methylation on the stabi

Effect of O(2′)-methylation on the stability of polynucleotide helices

✍ N. Yathindra; M. Sundaralingam 📂 Article 📅 1979 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 551 KB

## Abstract The effect of ribose(O2′)‐methylation on the stability of (O2′)‐methylated polyribonucleotide helices has been studied by conformational energy calculations. The preferred orientation of the methyl group is found to further stabilize the helical phosphodiester conformation (__g__^−^,__g

Effects of backbone modification on heli

Effects of backbone modification on helical peptides: The reduced carbonyl modification

✍ Chi-Fon Chang; Micheal H. Zehfus 📂 Article 📅 1998 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 148 KB 👁 1 views

Reducing a CO to a CH 2 moiety in a peptide bond destroys the ability of the peptide link to act as a proton acceptor in a hydrogen-bonded structure. Here, this modification is introduced into different positions of the helical peptide, acetyl-WGG(RAAAA) 4 R-amide, and the melting of these peptides

Terminal effect of chiral residue on hel

Terminal effect of chiral residue on helical screw sense in achiral peptides

✍ Yoshihito Inai; Yuji Kurokawa; Tadamichi Hirabayashi 📂 Article 📅 1999 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 221 KB 👁 1 views

To understand the terminal effect of chiral residue for determining a helical screw sense, we adopted five kinds of peptides I-V containing N-and/or C-terminal chiral Leu residue(s): Boc-D-Leu-(Aib-⌬Phe) 2 -L-Leu-OMe (IV), and Boc-D-Leu-(Aib-⌬Phe) 2 -Aib-OMe (V). The segment -(Aib-⌬Phe) 2 -was used

An NMR Investigation of the Conformation

An NMR Investigation of the Conformational Effect of Nitroxide Spin Labels on Ala-Rich Helical Peptides

✍ Kimberly A. Bolin; Paul Hanson; Sarah J. Wright; Glenn L. Millhauser 📂 Article 📅 1998 🏛 Elsevier Science 🌐 English ⚖ 151 KB

Nitroxide spin labels, in conjunction with electron spin reso- (1)(2)(3). In addition to probing the nature of the equilibrium nance (ESR) experiments, are extensively employed to probe the between aand 3 10 -helices in linear peptides (4-6), MTSSL structure and dynamics of biomolecules. One of the

Effect of amino acid substitution in amp

Effect of amino acid substitution in amphiphilic α-helical peptides on peptide–phospholipid membrane interaction

✍ Takuro Niidome; Shingo Anzai; Junko Sonoda; Yoko Tokunaga; Masaaki Nakahara; Tom 📂 Article 📅 1999 🏛 John Wiley and Sons 🌐 English ⚖ 137 KB 👁 1 views

It was previously found that a cationic amphiphilic peptide, Ac-(Leu-Ala-Arg-Leu) 3 -NHCH 3 (4 3 ), caused the destabilization of a phospholipid membrane and showed strong antibacterial activity [Lee et al. Biochim. Biophys. Acta 1986; 862: 211 -219]. In order to investigate the effect of changing h