Open AccessIsolation, purification, crystallization and preliminary crystallographic studies of amaryllin, a plant pathogenesis‐related protein from Amaryllis belladonna
Author(s) -
Kumar Sanjit,
Singh Nagendra,
Sinha Mau,
Kaur Punit,
Srinivasan A.,
Sharma Sujata,
Singh T. P.
Publication year - 2009
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s174430910901745x
Subject(s) - edman degradation , orthorhombic crystal system , ammonium sulfate , biology , crystallization , fusarium oxysporum , peptide sequence , botany , chemistry , biochemistry , chromatography , crystallography , crystal structure , organic chemistry , gene
A novel antifungal protein, amaryllin, has been isolated from the underground bulbs of Amaryllis belladonna , purified to homogeneity and crystallized. The protein was extracted using ammonium sulfate fractionation. The purified protein samples indicated a molecular weight of 15 kDa on SDS–PAGE. The protein showed antifungal activity against Aspergillus flavus and Fusarium oxysporum . The N‐terminal sequence of the first 15 amino‐acid residues was determined using Edman degradation and did not show significant sequence identity to any known protein. The protein was crystallized using the hanging‐drop vapour‐diffusion method with 30% PEG 8000 as precipitating agent. The crystals diffracted to 2.7 Å resolution and belonged to the orthorhombic space group I 222 or I 2 1 2 1 2 1 , with unit‐cell parameters a = 48.6, b = 61.9, c = 79.6 Å. The complete sequence and structure determination of amaryllin are in progress.