RESUMO
A protein with a molecular weight of 60,000 (60K) constitutes approximately 20% of the envelope protein of Azotobacter vinelandii. This protein was removed from cells and purified from other proteins by a simple washing procedure that had no effect on cell viability. Anti-60K antiserum blocked azotophage A-22 adsorption and agglutinated both vegetative cells and cysts; ferritin-conjugated antibodies used in indirect labeling studies bound uniformly to the periphery of vegetative cells. We conclude that 60K is present on the outer surface of vegetative cells and cysts. The protein is similar to the surface protein alpha of Acinetobacter ssp. in molecular weight, reassociation characteristics, and high ratio of acidic to basic amino acids. We propose that 60K forms a layer external to the outer membrane of A. vinelandii.
Assuntos
Azotobacter/ultraestrutura , Proteínas de Bactérias/análise , Testes de Aglutinação , Aminoácidos/análise , Proteínas de Bactérias/imunologia , Bacteriófagos , Membrana Celular/análise , Imunofluorescência , ImunodifusãoRESUMO
Colony dimorphism in a conditional nitrogen-fixing mutant of Azotobacter vinelandii was directly influenced by fixed nitrogen and oxygen partial pressure and may be related to the production of internal peripheral membrane.
