The PO protein. The major glycoprotein of peripheral nerve myelin.
A glycoprotein, referred to as PO protein, was isolated from rabbit sciatic nerve myelin by gel filtration on Agarose 0.5 m in dodecyl sulfate. The purified myelin was first defatted and extracted at pH 2. The water-soluble proteins such as myelin basic protein and P2 protein were extracted leaving a glycoprotein-rich residue, from which the PO protein was isolated. The purified protein showed a single band on gel electrophoresis in dodecyl sulfate when stained with Coomassie Blue of periodic acid-Schiff reagent. The carbohydrate, comprising 6.3% by weight, appears to exist as a nonasaccharide unit having 3 mannose, 3 N-acetylglucosamine, 1 sialic acid, 1 galactose and 1 fucose residue. The polypeptide moiety has a high content of non-polar amino acids. A single amino acid, isoleucine, was found at the NH2-terminal end by dansyl and Edman procedures. The PO protein is the major protein of peripheral nerve myelin.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D006023:Glycoproteins / Q000302:isolation & purification; D008970:Molecular Weight; D009185:Myelin Proteins / Q000302:isolation & purification; D009186:Myelin Sheath / Q000032:analysis*; D011817:Rabbits; D012584:Sciatic Nerve / Q000032:analysis*
D000596:Amino Acids; D002241:Carbohydrates; D006023:Glycoproteins; D009185:Myelin Proteins