
Binding assay and preliminary X‐ray crystallographic analysis of ACTIBIND, a protein with anticarcinogenic and antiangiogenic activities
Author(s) -
De Leeuw Marina,
Roiz Levava,
Smirnoff Patricia,
Schwartz Betty,
Shoseyov Oded,
Almog Orna
Publication year - 2007
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309107034483
Subject(s) - crystallography , rnase p , chemistry , biochemistry , rna , gene
ACTIBIND is a T2 RNase extracellular glycoprotein produced by the mould Aspergillus niger B1 (CMI CC 324626) that possesses anticarcinogenic and antiangiogenic activities. ACTIBIND was found to be an actin‐binding protein that interacts with rabbit muscle actin in a 1:2 molar ratio (ACTIBIND:actin) with a binding constant of 16.17 × 10 4 M −1 . Autoclave‐treated ACTIBIND (EI‐ACTIBIND) lost its RNase activity, but its actin‐binding ability was conserved. ACTIBIND crystals were grown using 20% PEG 3350, 0.2 M ammonium dihydrogen phosphate solution at room temperature (293 K). One to four single crystals appeared in each droplet within a few days and grew to approximate dimensions of 0.5 × 0.5 × 0.5 mm after about two weeks. Diffraction studies of these crystals at low temperature (100 K) indicated that they belong to the P 3 1 21 space group, with unit‐cell parameters a = 78, b = 78, c = 104 Å.