title: Comparison of the amino acid compositions and antigenic properties of spiralins purified from the plasma membranes of different spiroplasmas.
abstract: Spiralins were purified by agarose-suspension electrophoresis after extraction with detergents from the membranes of the following spiroplasmas: Spiroplasma citri C189, S. citri Maroc (R8A2), S. citri Scaph and the honey-bee spiroplasma B88. The four proteins (molecular mass congruent to 26,000 daltons, as determined by sodium dodecyl sulphate-pore gradient electrophoresis) showed very similar amino acid compositions characterized by the absence of methionine and tryptophan and a high polarity index (greater than 49%). When compared with the amino acid composition of S. citri membrane, the four spiralins had little or no histidine, a low content of glycine, leucine, tyrosine, phenylalanine and arginine, and a high content of threonine, alanine and valine. Comparison of the amino acid compositions according to the criteria described by Cornish-Bowden (Anal. Biochem., 1980, 105, 233-238) strongly suggests that all four spiralins are related. A crossed immunoelectrophoretical comparison, however, shows that though the three proteins purified from S. citri strains (serogroup I-1) are antigenically similar, they do not seem to share common epitopes with spiralin from the honey-bee spiroplasma B88 (serogroup I-2).
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D000942:Antigens, Bacterial / Q000032:analysis*; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000032:analysis* / Q000276:immunology; D002462:Cell Membrane / Q000032:analysis; D000939:Epitopes / Q000032:analysis*; D008565:Membrane Proteins / Q000032:analysis* / Q000276:immunology; D013149:Spiroplasma / Q000145:classification* / Q000276:immunology
chemical_list: D000596:Amino Acids; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D000939:Epitopes; D008565:Membrane Proteins; C028588:spiralin