Polypeptide helices in hybrid peptide sequences.
نویسندگان
چکیده
A new class of polypeptide helices in hybrid sequences containing alpha-, beta-, and gamma-residues is described. The molecular conformations in crystals determined for the synthetic peptides Boc-Leu-Phe-Val-Aib-betaPhe-Leu-Phe-Val-OMe 1 (betaPhe: (S)-beta3-homophenylalanine) and Boc-Aib-Gpn-Aib-Gpn-OMe 2(Gpn: 1-(aminomethyl)cyclohexaneacetic acid) reveal expanded helical turns in the hybrid sequences (alpha alphabeta)n and (alphagamma)n. In 1, a repetitive helical structure composed of C14 hydrogen-bonded units is observed, whereas 2 provides an example of a repetitive C12 hydrogen-bonded structure. Using experimentally determined backbone torsion angles for the hydrogen-bonded units formed by hybrid sequences, we have generated energetically favorable hybrid helices. Conformational parameters are provided for C11, C12, C13, C14, and C15 helices in hybrid sequences.
منابع مشابه
Gabapentin: A Stereochemically Constrained γ Amino Acid Residue in Hybrid Peptide Design
Nature has used the all-R-polypeptide backbone of proteins to create a remarkable diversity of folded structures. Sequential patterns of 20 distinct amino acids, which differ only in their side chains, determine the shape and form of proteins. Our understanding of these specific secondary structures is over half a century old and is based primarily on the fundamental elements: the Pauling R-hel...
متن کاملExpanding the polypeptide backbone: hydrogen-bonded conformations in hybrid polypeptides containing the higher homologues of a-amino acids
Half a century has passed since the hydrogen-bonded secondary structures of polypeptides and proteins were first recognized. An extraordinary wealth of conformational information is now available on peptides and proteins, which are formed of a-amino acid residues. More recently, the discovery of well-folded structures in oligopeptides containing b-amino acids has focused a great deal of current...
متن کاملExpanding the polypeptide backbone: hydrogen-bonded conformations in hybrid polypeptides containing the higher homologues of alpha-amino acids.
Half a century has passed since the hydrogen-bonded secondary structures of polypeptides and proteins were first recognized. An extraordinary wealth of conformational information is now available on peptides and proteins, which are formed of alpha-amino acid residues. More recently, the discovery of well-folded structures in oligopeptides containing beta-amino acids has focused a great deal of ...
متن کاملEngineering polypeptide folding through trans double bonds: transformation of miniature β-meanders to hybrid helices.
Utilization of conjugated double bonds to engineer the novel folded miniature β-meander type structures, single step transformation of miniature β-meanders into ααγ(4)-hybrid peptide 10/12-helices using catalytic hydrogenation, their solution and single crystal conformations are reported.
متن کاملIdentification of a mammalian angiopoietin-related protein expressed specifically in liver.
Based on searches of EST databases for signal sequences and amphipathic helices, we have identified and cloned an angiopoietin-like gene, ANGPTL3. Multiple tissue Northern blots show that ANGPTL3 is expressed principally in the liver. ANGPTL3 is expressed early during liver development, and expression is maintained in adult liver. Human ANGPTL3 is a 460-amino-acid polypeptide with the character...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of the American Chemical Society
دوره 127 47 شماره
صفحات -
تاریخ انتشار 2005