Self-aggregation of squid cranial cartilage proteoglycans

Squid cranial cartilage has been found to contain three different proteoglycan populations, two of which form aggregates (Vynios, D.H. and Tsiganos, C. P., Biochim. Biophys. Acta 1033: 139-147, 1990). The aggregation involves interaction of their protein cores as assessed by electron microscopy and biochemical data. Aggregating oligopeptides were isolated after mild trypsin digestion which inhibited self-aggregation of proteoglycans. The aggregation does not involve interaction of the side chains of polar amino acids and evidence is provided that it is mediated through hydrophobic interaction. It is enhanced upon concentration or incubation of the samples at 37 degrees C.