X-ray study of herbaspirilum seropedicae GlnB protein adsorbed on silicon

Abstract

GlnB-Hs protein is a globular member of PII-like family involved in the nitrogen control fixation in diazothoph organisms like H. seropedicae. In this work, GlnB-Hs is deposited by spin-coating on Si (in) and its self-assembling is investigated by AFM (atomic force microscopy) and X-ray at grazing incidence angles. GlnB-Hs forms circular 100 nm to 150 nm wide face-up donut shaped protein aggregates on silicon. Reflectivity and diffraction profiles from the protein deposits on Si(111) and Si(100), suggest ordered domains that are stable under the X-ray beam and have d-spacing compatible with protein dimensions already determined by classical protein crystallography. Copyright © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.