Antibodies against recombinant heat shock proteins of 60 kDa from enterobacteria in the sera and synovial fluid of HLA-B27 positive ankylosing spondylitis patients.

OBJECTIVE: To study the association of HLA-B27 with IgG antibodies to different enterobacterial HSP60s in patients with ankylosing spondylitis (AS). METHODS: IgG antibodies to 60 kDa enterobacterial HSPs were determined by ELISA in paired samples of sera and synovial fluid from 21 HLA-B27+ ankylosing spondylitis (AS) patients; and in sera from 32 HLA-B27+ AS patients, 35 HLA-B27+ healthy relatives of AS patients, and 60 HLA-B27- healthy individuals with no family members with AS. RESULTS: HLA-B27+ patients and healthy individuals showed significantly higher IgG antibody levels to recombinant enterobacterial HSP60s than HLA-B27- healthy controls. The levels of anti-HSP60Sf and anti-HSP60Ec antibodies correlated with disease activity and anti-HSP60Ec antibodies with male gender. No association between enterobacterial HSP60 antibody levels and disease duration was observed. All groups had lower levels of IgG antibodies to rHSP60 from Streptococcus pyogenes (rHSP60 Spy). In paired samples of sera and synovial fluid from B27+ patients, IgG antibodies to enterobacterial HSP60s were detected, but in significantly higher levels in sera than in synovial fluid. The anti-rHSPSpy IgG response in these samples was lower and similar in the three groups. CONCLUSIONS: A correlation was found between HLA-B27 and the response to recombinat enterobacterial HSP60s. This response could be associated with disease activitir and gender in some proteins and the presence eof IgG antibodies to these proteins in synovial fluid could be associated with the inflammatory process and initiation of AS.

Purification and characterization of a probable light receptor with kinase activity from beet root plasma membranes.

A 120-kDa glycoprotein was found in beet root (Beta vulgaris L.) plasma membranes. This protein could be phosphorylated in a Ca2+-independent manner. Its carbohydrate moiety was composed of both O-linked galactose-beta(1-3)-N-acetylgalactosamine disaccharides (which bind peanut agglutinin) and N-linked concanavalin A (ConA)-binding oligosaccharides. The phosphorylation of this protein was rapid, half-saturated with 6 microM ATP and higher at alkaline pH values. This protein was phosphorylated more efficiently with Mn-ATP as substrate than with Mg-ATP. This phosphorylation increased when plasma membranes were illuminated with low-fluence blue light, a fact suggesting that the 120-kDa glycoprotein could be similar to phototropin: a blue-light photoreceptor involved in phototropism. This protein was purified using a ConA-Sepharose column. The phosphorylation of the purified protein could be observed, but it was much lower than that of the 120-kDa protein in plasma membranes. In addition, it was not enhanced by light. Some possible explanations for this photosensitivity loss are discussed.