Chemical and Optical Properties of Nerve Proteins

Abstract

Previous experiments on thermal shortening and on solvation and desolvation of medullated and non-medullated nerves indicated the presence of oriented protein primary valence chains in these nerves. 1 Similar oriented structures are present in most fibrous tissues. 2 To characterize these structures chemically and to localize them morphologically, experiments have been performed on the chemical and optical properties of normal nerves, of nerves which have been extracted in a variety of ways, and of fibers artificially spun from protein extracts of nerves. The present paper is a preliminary report of this work.

Because of certain difficulties inherent in the procedure of extraction in the case of medullated nerves, and in order to investigate axis cylinder material in as nearly pure form as possible we have turned to non-medullated nerves of the claws and legs of lobsters. The extractions indicate that essentially the same 3 nucleoproteins that McGregor 3 isolated from mammalian central nervous systems are to be found also in lobster nerves. Of particular significance in this connection is the third nucleoprotein extractable at pH 13 to 14. This appears to be the protein which has been called neurostromin by Shkarin. 4 After complete extraction of all proteins soluble below pH 13, the individual finely cut nerve bits still retain their original shape and general structure remarkably. Moreover, such extracted nerve bits display thermal shortening to an extraordinary degree. Although it is impossible to state that other proteins are not involved in thermal shortening of lobster nerve, neurostromin must play the major rôle in the phenomenon.