scholarly journals Helix Formation in Preorganized β/γ-Peptide Foldamers: Hydrogen-Bond Analogy to the α-Helix without α-Amino Acid Residues

2010 ◽  
Vol 132 (23) ◽  
pp. 7868-7869 ◽  
Author(s):  
Li Guo ◽  
Aaron M. Almeida ◽  
Weicheng Zhang ◽  
Andrew G. Reidenbach ◽  
Soo Hyuk Choi ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Amino Acid ◽  
Amino Acid Residues ◽  
Helix Formation ◽  
Α Helix

Conformation of branched polypeptides based on poly(L-lysine): The effect of terminal amino acids in the branches

1985 ◽  
Vol 50 (1) ◽  
pp. 228-244 ◽  
Author(s):  
Hana Votavová ◽  
Ferenc Hudecz ◽  
Judit Kajtár ◽  
Jaroslav Šponar ◽  
Karel Bláha ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ionic Strength ◽  
Glutamic Acid ◽  
Amino Acid Residues ◽  
Ordered Structure ◽  
Cd Spectra ◽  
Helix Formation ◽  
Terminal Amino ◽  
Α Helix

CD Spectra of branched polypeptides based on poly(L-lysine) and containing three DL-alanine residues and one to three other L- or D-amino acid residues in the branches were measured in water, water-methanol and water-trifluoroethanol mixtures. In aqueous solutions dependence of the CD spectra on pH and ionic strength was studied. The effect of branch elongation was followed mainly with compounds containing glutamic acid. One terminal D-amino acid residue and also an extension by two L- or D-amino acid residues does not hinder the α-helix formation in the backbone but affects the conditions of its formation. In polypeptides with three L- or D-amino acids additional α-helical segments in the branches are assumed to be formed. For branches with L-amino acids the CD curves express additively the contributions of both helical components, in the case of D-amino acids the increasing population of the ordered structure in branches is manifested by compensation of dichroic contribution of the L-amino acid backbone leading even to enantiomorphous curves.

Modèle topologique de la structure d’un antiport vacuolaire de type NHX chez la vigne cultivée (Vitis vinifera)

Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 339-347 ◽  
Author(s):  
Mohsen Hanana ◽  
Olivier Cagnac ◽  
Ahmed Mliki ◽  
Eduardo Blumwald
Keyword(s):  
Amino Acid ◽  
Vitis Vinifera ◽  
Molecular Mass ◽  
Electrostatic Interactions ◽  
Functional Characterization ◽  
Terminal Region ◽  
Vitis Vinifera L ◽  
Amino Acid Residues ◽  
Transmembrane Segments ◽  
Α Helix

After identifying and isolating a grapevine ( Vitis vinifera L.) NHX vacuolar antiporter and before initializing functional genomic studies, we juged necessary to acquire a minimum of knowledge about the VvNHX1 protein. Thus, we realized a bioinformatic analysis to determine its basic characteristics and to get structural informations that could guide us through the functional characterization. We have determined important physico-chemical parameters (molecular mass, isoelectric point, hydrophobic regions, etc.) and obtained interesting structural data (primary, secondary, and tertiary structures; conserved domains and interaction motives; etc.). The VvNHX1 gene, which encodes this 541 amino-acid protein with a predicted molecular mass of 60 kDa, is made of 14 exons and measures 6.5 kb. The amino-acidic composition of this protein is very important, in particular, for the establishment of the α-helix structure, which represents more than 50% of the protein, but also for charge distribution, which generates critical electrostatic interactions for the ionic flux. The secondary structure of VvNHX1 contains multiple transmembrane α-helix segments that are made of hydrophobic amino-acid residues, thus facilitating its insertion in the membrane. Globally, VvNHX1 has one hydrophobic N-terminal region, made of 10 transmembrane segments with 440 amino-acid residues, and one hydrophilic C-terminal region, made of 100 residues. The region located between the fourth and fifth transmembrane segments represents, with its structure mainly helicoidal and the presence of a favourable electrostatic environment, the pore where cation flux is performed across the membrane. VvNHX1 contains various interaction domains as well as several putative posttranslational modification sites, mainly at the C-terminus but also at the N-terminus, that play an important part in regulating protein activities, influence protein structural stability, or interact with other proteins or signalling molecules.

scholarly journals Reversible α-helix formation controlled by a hydrogen bond surrogate

Tetrahedron ◽  
2012 ◽  
Vol 68 (23) ◽  
pp. 4434-4437 ◽  
Author(s):  
Stephen E. Miller ◽  
Neville R. Kallenbach ◽  
Paramjit S. Arora
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bond Surrogate ◽  
Helix Formation ◽  
Α Helix

scholarly journals Noncharged amino acid residues at the solvent-exposed positions in the middle and at the C terminus of the α-helix have the same helical propensity

2003 ◽  
Vol 12 (6) ◽  
pp. 1169-1176 ◽  
Author(s):  
Dmitri N. Ermolenko ◽  
John M. Richardson ◽  
George I. Makhatadze
Keyword(s):  
Amino Acid ◽  
Amino Acid Residues ◽  
C Terminus ◽  
Α Helix

scholarly journals Hydrogen Bond Strengths in Phosphorylated and Sulfated Amino Acid Residues

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e57804 ◽  
Author(s):  
Chaya Rapp ◽  
Hadassa Klerman ◽  
Emily Levine ◽  
Christopher L. McClendon
Keyword(s):  
Hydrogen Bond ◽  
Amino Acid ◽  
Amino Acid Residues ◽  
Bond Strengths

scholarly journals New 19-Residue Peptaibols from Trichoderma Clade Viride

2018 ◽  
Vol 6 (3) ◽  
pp. 85 ◽  
Author(s):  
Tamás Marik ◽  
Chetna Tyagi ◽  
Gordana Racić ◽  
Dávid Rakk ◽  
András Szekeres ◽  
...  
Keyword(s):  
Amino Acid ◽  
Structural Investigation ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Helix Formation ◽  
Left Handed ◽  
Wall Structures ◽  
High Preference ◽  
Wide Range ◽  
Unusual Amino Acid

Trichoderma koningiopsis and T. gamsii belong to clade Viride of Trichoderma, the largest and most diverse group of this genus. They produce a wide range of bioactive secondary metabolites, including peptaibols with antibacterial, antifungal, and antiviral properties. The unusual amino acid residues of peptaibols, i.e., α-aminoisobutyric acid (Aib), isovaline (Iva), and the C-terminal 1,2-amino alcohol make them unique among peptides. In this study, the peptaibiomes of T. koningiopsis and T. gamsii were investigated by HPLC-ESI-MS. The examined strains appeared to produce 19-residue peptaibols, most of which are unknown from literature, but their amino acid sequences are similar to those of trikoningins, tricholongins, trichostrigocins, trichorzianins, and trichorzins. A new group of peptaibols detected in T. koningiopsis are described here under the name “Koningiopsin”. Trikoningin KA V, the closest peptaibol compound to the peptaibols produced by these two strains, was selected for structural investigation by short MD simulation, which revealed that many residues show high preference for left handed helix formation. The bioactivity of the peptaibol mixtures produced by T. koningiopsis and T. gamsii was tested on agar plates against bacteria, yeasts, and filamentous fungi. The results revealed characteristic differences in bioactivities towards the different groups of target microorganisms, which can be explained with the differences in their cell wall structures.

Sign in / Sign up

Export Citation Format

Share Document