The objective of the proposed research is to continue the characterization of glycoproteins and proteoglycans that undergo axonal transport to specific axonal and synaptic subfractions of the goldfish optic nerve. Synaptic fractions to be analyzed include soluble, synaptic vesicle, synaptic plasma membrane, and synaptic junctions. Methods of analysis of glycoproteins will include lectin affinity chromatography and one and two dimensional SDS gel electrophoresis. Glycopeptides derived from transported glycoproteins by proteolytic digestion will be evaluated by differential affinity to concanavalin A and susceptability to hydrolysis with alkaline borohydride. Soluble proteoglycans and particulate proteoglycans extracted with deoxycholate or guanidine will be separated by ion exchange chromatography, density gradient centrifugation and gel filtration and will be subjected to analysis of the type, size, and charge density of constituent glycosaminoglycan chains. Separate studies will evaluate the effect of physiological activity on transported glycoprotein turnover and will attempt to purify and immunocytochemically localize glycoproteins concentrated in isolated myelin. The significance of the proposed studies will be the clarification of the types of glycosylated macromolecules localized at functionally important regions of the axon and nerve terminal. Identification of such molecules and evaluation of their turnover should be a first step in elucidating their specific functions in neuron activity.
