Further characterization of axonally transported proteoglycans.

We report further analysis of axonally transported proteoglycans in soluble and membranous subfractions of goldfish optic tectum. Distribution of transported 35SO4 radioactivity was 35.2% soluble, 63.4% Triton-NaCl extractable and 1.4% unextracted. Proteoglycans isolated on DEAE cellulose were treated with chondroitinase AC or nitrous acid and remaining heparan sulfate proteoglycans (HSPGs) and chondroitin sulfate proteoglycans (CSPGs) were sized on Sepharose CL-6B. Kav values and estimated molecular weights were: Soluble CSPG-0.36 (160 kDa), Triton-NaCl extracted CSPG-.031 (200 kDa), Soluble HSPG-0.37 (150 kDa), Triton-NaCl extracted HSPG-0.37 (150 kDa). For constituent CS and HS chains the Kav values and estimated molecular weights on CL-6B were: Soluble CS-0.55 (15 kDa), Triton-NaCl extracted CS-0.55 (15 kDa), Soluble HS-0.59 (13 kDa) and Triton-NaCl extracted HS-0.65 (9 kDa). CS was shown to be sulfated exclusively at carbon 4 for both soluble and Triton NaCl extracted fractions.