Acta Crystallographica Section D

Biological Crystallography

Volume 58, Part 4 (April 2002)

crystallization papers

Acta Cryst. (2002). D58, 683-686 [ doi:10.1107/S090744490200166X ]

Expression, purification and preliminary crystallographic studies of -amylase isozyme 1 from barley seeds

X. Robert, T. E. Gottschalk, R. Haser, B. Svensson and N. Aghajari

Abstract: The germinating barley seed contains two major [alpha] -amylase isozyme families, AMY1 and AMY2, involved in starch degradation to provide energy used by the plant embryo for growth. Many years of difficulty in growing three-dimensional crystals of natural AMY1 have now been overcome by a nonapeptide truncation of the enzyme C-terminus. The truncated enzyme was overexpressed in Pichia pastoris, purified and crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol 8000 as precipitant and 2-propanol as an additive. Crystals belong to the orthorhombic space group P2₁2₁2, with unit-cell parameters a = 88.36, b = 72.82, c = 61.74 Å and one molecule per asymmetric unit.

Keywords: -amylase isozyme 1.