1ioc

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spinqualitylabelsall models 1ioc, resolution 2.4Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF MUTANT HUMAN LYSOZYME, EAEA-I56T

Contents 1 Overview 2 Disease 3 About this Structure 4 Reference

Overview

To understand the mechanism of amyloid fibril formation of a protein, we examined wild-type and three mutant human lysozymes containing both amyloidogenic and non-amyloidogenic proteins: I56T (amyloidogenic); EAEA, which has four additional residues (Glu-Ala-Glu-Ala-) at the N-terminus located on a beta-structure; and EAEA-I56T, which is an I56T mutant of EAEA. All formed amyloid-like fibrils through an in the increase contents of alpha-helix with increasing concentration of ethanol. The order of propensity for amyloid-like fibril formation in highly concentrated ethanol solution is EAEA-I56T > EAEA > I56T > wild-type. This order is almost the reverse of the order of conformational stability of these proteins, wild-type > EAEA > I56T > EAEA-I56T. The important views in this work are as follows. (i) Artificially modified proteins formed amyloid fibrils in vitro. This means that amyloid formation is a generic property of polypeptide chains. (ii) The amyloidogenic mutation Ile56 to Thr caused the destabilization and promoted fibril formation in the wild-type and EAEA human lysozymes, indicating that instability facilitates amyloid formation. (iii) The mutant protein EAEA human lysozyme had higher propensity for fibril formation than the amyloidogenic mutant protein, indicating that amyloid formation is controlled not only by stability but also by other factors. In this case, appending polypeptide chains to a beta-structure accelerated amyloid formation.

Disease

Known diseases associated with this structure: Amyloidosis, renal OMIM:[153450], Microphthalmia, syndromic 1 OMIM:[309800]

About this Structure

1IOC is a Single protein structure of sequence from Homo sapiens with as ligand. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.

Reference

Elongation in a beta-structure promotes amyloid-like fibril formation of human lysozyme., Goda S, Takano K, Yamagata Y, Maki S, Namba K, Yutani K, J Biochem. 2002 Oct;132(4):655-61. PMID:12359083

Page seeded by OCA on Thu Feb 21 13:13:53 2008