Two-dimensional crystallization of catalase on a monolayer film of poly(1-benzyl-L-histidine) spread at the air/water interface.
Two-dimensional (2D) crystals of beef liver catalase were prepared by adsorption to a film of synthetic polypeptide, poly(1-benzyl-L-histidine) (PBLH), spread at the air/water interface. The crystallization experiments were carried out in the pH range of 4.8-6.4 for catalase solutions at low concentration (10 micrograms/ml). The pH-dependence suggested an electrostatic interaction in the binding of catalase to the PBLH film. At lower pH, small crystals were formed at a low binding rate, and at higher pH the binding was rapid and densely-packed 2D arrays with poor crystallinity were formed. To stimulate crystal growth, a thermal treatment was applied. One-shot heating of the interfacial catalase-PBLH film to 35-40 degrees C was remarkably effective to form larger 2D crystals. The structure of catalase 2D crystals has been analyzed by Fourier filtering of the transmission electron micrographs. The crystal form is a new one, containing four catalase molecules in the unit cell with lattice parameters of alpha = 187 A, b = 225 A and gamma = 92.8 degrees.
Sato
A
A
Frontier Research Program, Institute of Physical and Chemical Research (RIKEN), Saitama, Japan.
Furuno
T
T
Toyoshima
C
C
Sasabe
H
H
D000818:Animals; D002374:Catalase / Q000737:chemistry* / Q000648:ultrastructure; D002417:Cattle; D003460:Crystallization; D003461:Crystallography; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D010455:Peptides; D013696:Temperature
D010455:Peptides; C080171:poly(1-benzylhistidine); D002374:Catalase