The measurement of negative charge content in cartilage using a colloid titration technique

• Published in: Analytical biochemistry Vol. 204; no. 2; pp. 250 - 257
• Main Authors: Van Damme, M-P.I., Blackwell, S.T., Murphy, W.H., Preston, B.N.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.08.1992; Elsevier
• Subjects: Analytical biochemistry: general aspects, technics, instrumentation; Analytical, structural and metabolic biochemistry; Animals; Barium - chemistry; Biological and medical sciences; cartilage; Cartilage - chemistry; Cartilage, Articular - chemistry; Cartilage, Articular - ultrastructure; Cattle; charge; Colloids; content; Cyclohexanones - chemistry; Dextran Sulfate - chemistry; Electric Conductivity; Fundamental and applied biological sciences. Psychology; Glycosaminoglycans - chemistry; In Vitro Techniques; measurement; Nasal Septum - chemistry; negative; Polymers - chemistry; Sulfates - chemistry; Tolonium Chloride - chemistry; Proteoglycan; Cartilage; Carboxylate; pH; Environmental factor; Glycosaminoglycan; Sulfates; Colloid; Comparative study; Quantitative analysis
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/0003-2697(92)90235-Y

A colloid titration technique has been used to determine the sulfate and carboxylate content of various glycosaminoglycans and has been validated by comparing the results with data obtained using well-established techniques. The method has been applied to the measurement of the negative charge content of cartilage slices at various depths from the articular surface and to the determination of sulfate and carboxylate contents in bovine nasal septa. Titrations of nasal septa were performed on milled cartilage, on cartilage digested with papain and on proteoglycans purified by cesium chloride gradient centrifugation of guanidinium chloride extracts. The sulfate content was similar for all three preparations (0.5 μeq per milligram dry cartilage). However, the carboxylate content determined on milled cartilage was 40% higher than that obtained for cartilage digested with papain or for purified proteoglycans; this implies the possible contribution of carboxyl groups from structural glycoproteins present in the extracellular matrix. The carboxylate content determined on purified proteoglycans was in excellent agreement with values calculated from chemical analyses.