Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
COUPLING BETWEEN FOLDING AND IONIZATION EQUILIBRIA - EFFECTS OF PH ONTHE CONFORMATIONAL PREFERENCES OF POLYPEPTIDES
Autore:
RIPOLL DR; VOROBJEV YN; LIWO A; VILA JA; SCHERAGA HA;
Indirizzi:
CORNELL UNIV,BAKER LAB CHEM ITHACA NY 14853 CORNELL UNIV,BAKER LAB CHEM ITHACA NY 14853 CORNELL UNIV,CORNELL THEORY CTR ITHACA NY 14853 NOVOSIBIRSK BIOORGAN CHEM INST NOVOSIBIRSK 630090 RUSSIA UNIV GDANSK,DEPT CHEM PL-80952 GDANSK POLAND UNIV NACL SAN LUIS,FAC CIENCIAS FIS MATEMAT & NAT,INST MATEMAT APLICADA SAN LUIS RA-9505700 SAN LUIS ARGENTINA
Titolo Testata:
Journal of Molecular Biology
fascicolo: 4, volume: 264, anno: 1996,
pagine: 770 - 783
SICI:
0022-2836(1996)264:4<770:CBFAIE>2.0.ZU;2-K
Fonte:
ISI
Lingua:
ENG
Soggetto:
OCCURRING AMINO-ACIDS; POISSON-BOLTZMANN EQUATION; MULTIPLE-MINIMA PROBLEM; HYDROGEN-BOND INTERACTIONS; COIL STABILITY-CONSTANTS; ALANINE-BASED PEPTIDES; MONTE-CARLO METHOD; NONBONDED INTERACTIONS; ENERGY PARAMETERS; AQUEOUS-SOLUTION;
Keywords:
POLYPEPTIDE CONFORMATION; CONFORMATIONAL SEARCH; ELECTROSTATIC; SOLVATION; ENERGY FUNCTIONS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
66
Recensione:
Indirizzi per estratti:
Citazione:
D.R. Ripoll et al., "COUPLING BETWEEN FOLDING AND IONIZATION EQUILIBRIA - EFFECTS OF PH ONTHE CONFORMATIONAL PREFERENCES OF POLYPEPTIDES", Journal of Molecular Biology, 264(4), 1996, pp. 770-783

Abstract

A new approach to the conformational study of polypeptides is presented. It considers explicitly the coupling between the conformation of the molecule and the ionization equilibria at-a given pH value. Calculations of the solvation free energy and free energy of ionization of a 17-residue polypeptide are carried out using a fast multigrid boundaryelement method (MBE). The MBE method uses an adaptive tessellation ofthe molecular surface by boundary elements with non-regular size to solve the Poisson equation rapidly, and with a high degree of accuracy. The MBE method is integrated into the ECEPP (Empirical ConformationalEnergy Program for Peptides) algorithm to compute the coupling between the ionization state and the conformation of the molecule. This approach has been applied to study the conformational preference of a short polypeptide for which the available NMR and CD experimental data indicate that conformations containing a right-handed alpha-helical segment are energetically moro favorable at low values of pH. The results of calculations using the present method agree quite well with experiments, in contrast to previous applications with standard techniques (using pre-assigned charges at each pH) that were not able to reproduce the experimental findings. Also, it is shown how the coupling to the conformation leads to different degrees of ionization of a given type ofresidue, for example glutamic acid, at-different positions in the amino acid sequence, at any given pH. The results of this study provide asound basis to discuss the origin of the stability of polypeptide conformations, and its dependence on the environmental conditions. (C) 1996 Academic Press Limited

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 16/07/20 alle ore 06:43:14