THE PURIFICATION OF A GROEL-LIKE STRESS PROTEIN FROM AEROBICALLY ADAPTED CAMPYLOBACTER-JEJUNI

From plate cultures of Campylobacter jejuni grown in room air a partic ulate protein of 62 kDa was isolated by ion-exchange chromatography. T he protein had a square shape from the side view but when viewed from the top it had a star-shaped structure. The molecular size of the whol e particle determined by gel filtration was 850 kDa which suggested th e presence of 14 subunits of 62 kDa in each particle. The N-terminal 3 7 amino residues showed more than 80% homology with the sequence of th ese heat shock protein (HSP) 60 homologs of Chlamydia trachomatis, Hel icobacter pylori, and Escherichia coli (GroEL). This protein is immuno logically cross-reactive with the antiserum for the 60-kDa HSP of Yers inia enterocolitica. Production of the 62-kDa protein increased under heat stress and growth in an aerobic atmospheric environment. From the se observations we concluded that the 62-kDa protein is a Campylobacte r stress protein (Cj62) which belongs to the HSP 60 family.