Cartilage-derived ribonucleotide binding activity.
Previous investigations of ribonucleotide binding activity in the sera of patients with connective tissue diseases unexpectedly identified binding to the single stranded nucleotide polyadenylic acid (Poly [A]) in osteoarthritic patients serving as control subjects. The basis for this response and the nature of the binding factor(s) were not evaluated. Hypothesizing that such activity may originate from diseased joint tissue and that its measurement would provide a valuable parameter to assess active cartilage catabolism, the present study examined the Poly (A) binding affinity of cartilage isolates. It was shown that low buoyant density associative cesium chloride gradient fractions of guanidine extracts of cartilage could bind to Poly (A). Activity appeared to be largely masked in native proteoglycan aggregates but could be identified in low buoyant density dissociative cesium chloride gradient fractions of aggregates. Chondroitin sulfate, hyaluronic acid and native and denatured cartilage collagen had a minimal binding affinity. By nucleotide absorption, a purine ring specificity was shown for the active binding factor. Using polyacrylamide slab gel elution and Poly (A) affinity chromatography, activity was localized to a 57 KDa protein.
Tangnijkul
Y
Y
Department of Internal Medicine, University of Cincinnati Medical Sciences Center, Ohio 45267.
Herman
J H
JH
D000818:Animals; D002358:Cartilage, Articular / Q000032:analysis / Q000378:metabolism*; D002417:Cattle; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D010003:Osteoarthritis / Q000097:blood; D011061:Poly A / Q000378:metabolism*; D011869:Radioligand Assay; D012265:Ribonucleotides / Q000378:metabolism*
D012265:Ribonucleotides; D011061:Poly A