ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract— Two basic peptides (B1 and B2) were derived from bovine spinal cord following in situ proteolysis at 37°C for 10–24 h. These peptides do not arise as degradation products from the A1 protein as shown by amino acid composition and end group analysis; rather they appear to originate from some larger basic protein in the spinal cord having similarities to the P2 protein, a basic protein found in peripheral nerve myelin. The peptides were purified following defatting, acid extraction, and ammonium sulphate fractionation, by chromatography on Amberlite IRC-50 resin using guanidinium chloride. The peptides, found generally in a 4:1 ratio of B1 to B2, appeared homogeneous on gel electrophoresis and immunodiffusion. Approximately 25–60 mg of peptides was obtained per 100 g wet spinal cord.In contrast to the basic A1 protein from myelin, neither of these peptides nor their pepsin digests were encephalitogenic. They do not cross-react immunologically with the basic A1 protein, but cross-react with each other. These peptides further differ from the A1 protein in their tryptic peptide map, size (B1, 63 residues; B2, 54 residues), and composition particularly the high lysine: arginine ratio, and low histidine content. Like the A1 protein, however, they contain a tryptophan residue and a blocked NH2-terminal amino acid; peptide Bl has COOH-terminal valine. It was concluded that the basic peptides represent a fragment of a hitherto unidentified protein(s) of the nervous system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1974.tb10749.x
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