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Dutzler, R; Schirmer, T; Karplus, M; Fischer, S (2002). Translocation mechanism of long sugar chains across the maltoporin membrane channel. Structure, 10(9):1273-84.

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Abstract

Maltoporin allows permeation of long maltodextrin chains. It tightly binds the amphiphilic sugar, offering both hydrophobic interactions with a helical lane of aromatic residues and H bonds with ionic side chains. The minimum-energy path of maltohexaose translocation is obtained by the conjugate peak refinement method, which optimizes a continuous string of conformers without applying constraints. This reveals that the protein is passive while the sugar glides screw-like along the aromatic lane. Near instant switching of sugar hydroxyl H bond partners results in two small energy barriers (of approximately 4 kcal/mol each) during register shift by one glucosyl unit, in agreement with a kinetic analysis of experimental dissociation rates for varying sugar chain lengths. Thus, maltoporin functions like an efficient translocation "enzyme," and the slow rate of the register shift (approximately 1/ms) is due to high collisional friction.

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Institute of Biochemistry
07 Faculty of Science > Institute of Biochemistry
DDC:570 Life sciences; biology
Language:English
Date:2002
Deposited On:17 Mar 2009 12:05
Last Modified:27 Nov 2013 20:23
Publisher:Elsevier
ISSN:0969-2126
Publisher DOI:10.1016/S0969-2126(02)00811-0
PubMed ID:12220498
Citations:Web of Science®. Times Cited: 39
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