Analysis of the secreted endothelial proteoglycans.

(A) Fractionation of the secreted proteoglycans for analysis. The Sepharose CL-6B fractions were pooled as indicated for analyses shown in the lower panels of this Figure. (B) Trypsin digestion of secreted proteoglycans. Trypsin digests of fractions 3 and 4, which contain the putative serglycin proteoglycans, were analyzed on Sepharose CL-6B. (C) GAGs associated with the secreted proteoglycans. The GAG chains were released from the core protein by alkaline digestion as described in the text and analyzed on Sepharose CL-6B columns. (D) Chondroitinase ABC digestion of secreted proteoglycans. The digests were performed as described in the text and analyzed on PD-10 (Sephadex G-25) columns.