Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Protonation of histidine and histidine-tryptophan interaction in the activation of the M2 ion channel from influenza A virus
Autore:
Okada, A; Miura, T; Takeuchi, H;
Indirizzi:
Tohoku Univ, Grad Sch Pharmaceut Sci, Sendai, Miyagi 9808578, Japan TohokuUniv Sendai Miyagi Japan 9808578 ci, Sendai, Miyagi 9808578, Japan
Titolo Testata:
BIOCHEMISTRY
fascicolo: 20, volume: 40, anno: 2001,
pagine: 6053 - 6060
SICI:
0006-2960(20010522)40:20<6053:POHAHI>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
INTEGRAL MEMBRANE-PROTEIN; SIDE-CHAIN CONFORMATION; CATION-PI INTERACTIONS; A VIRUS; TRANSMEMBRANE DOMAIN; SECONDARY STRUCTURE; INTRACELLULAR-TRANSPORT; CIRCULAR-DICHROISM; RAMAN-SPECTROSCOPY; AMINO-ACIDS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
48
Recensione:
Indirizzi per estratti:
Indirizzo: Takeuchi, H Tohoku Univ, Grad Sch Pharmaceut Sci, Sendai, Miyagi 9808578, Japan Tohoku Univ Sendai Miyagi Japan 9808578 Miyagi 9808578, Japan
Citazione:
A. Okada et al., "Protonation of histidine and histidine-tryptophan interaction in the activation of the M2 ion channel from influenza A virus", BIOCHEM, 40(20), 2001, pp. 6053-6060

Abstract

The M2 protein of influenza A virus forms a homotetramer ion channel in the lipid membrane. The channel is specific for proton conductance and is activated by low pH with a transition midpoint at pH 5.7. We have studied the structure of the transmembrane domain of the M2 ion channel by using UV resonance Raman spectroscopy, with special attention to the side chains of histidine (His37) and tryptophan (Trp41) residues. The Raman spectra provide direct evidence that the imidazole ring of His37 is protonated upon channel activation at low pH. Concomitantly, the UV resonance Raman scattering fromTrp41 shows an unusual intensity change, which is ascribed to a cation-pi interaction between the protonated (cationic) imidazole ring of His37 and the indole ring of Trp41. The protonation of His37 and the Raman intensity change of Trp41 do not occur in the presence of amantadine that blocks the M2 ion channel. These observations clearly show that the protonation of His37 and concomitant cation-iz interaction with Trp41 is a key step in the activation of the M2 ion channel. The His37-Trp41 interaction associated with the channel activation is explained by assuming a conformational transitionof His37 induced by electrostatic repulsion among the protonated imidazolerings of four His37 residues in the tetramer channel. Trp41 may play a role in stabilizing the channel open state through cation-pi interaction with His37. A molecular model for the activation of M2 ion channel is proposed on the basis of the gating mechanism.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/10/20 alle ore 11:50:54