When Both Individuals and Populations Search: Adding Simple Learning to the Genetic Algorithm

Rubella virus contains three major structural polypeptides designated E1, E2, and C with molecular weights of 62,000, 47,000-54,000 (a complex), and 38,000, respectively, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reduced conditions. Limited-digest peptide maps confirm that each of these polypeptides is distinct and the E2 is a series of three closely related glycopolypeptides. Both E1 and E2 are glycosylated and covalently incorporate 3Hpalmitic acid. Enzymatic digestion of intact virus with trypsin completely degrades both E1 and E2, while the C polypeptide remains intact. E1 has an isoelectric point of pH 6.5. E2 exhibits at least 15 different isoelectric species, which focus over the pH range of 5.0-8.6, and C has two distinct isoelectric species of pH 8.8 and pH 9.5. Under unreduced conditions, E1 exists as a disulfide-bonded dimer (E1-E1) with a molecular weight of 105,000; a disulfide-bounded heterodimer (E1-E2) with a molecular weight of 95,000; and in monomeric form (E1). E2 is found predominantly in heterodimeric form (E1-E2), and C is found only in dimeric form when unreduced. Functional-inhibition studies with selected monoclonal antibodies show at least three distinct antigenic domains on E1 that include sites involved in hemagglutination and lysis of red blood cells.