Cleveland Peptide Mapping Research Articles

Nitrate reductase-deficient mutants in barley: enzyme stability and peptide mapping

Thermal stability and pH optima of NADH-nitrate reductase-associated cytochrome c reductase and FMNH 2-nitrate reductase from wild type, cv Steptoe or Winer, and mutants nar 1d, nar 1g, nar 1h, Xno 18 and Xno 19 were compared to determine if structural differences in the nitrate reductase protein could be detected. Also, the nitrate reductase-associated cytochrome c reductase from nar 1d was purified and compared with the wild type by peptide mapping. The pH optimum for FMNH 2-nitrate reductase from Steptoe and nar 1h, and for NADH-cytochrome c reductase from Steptoe, nar 1d, nar 1g and nar 2a was 7.5. Thermal stabilities of the nitrate reductase-associated activities (FMNH 2-nitrate reductase or NADH-cytochrome c reductase) from nar mutants were less than the Steptoe wild type, while Xno mutants were equal to the Winer wild type. Cleveland peptide maps of nar 1d NADH-cytochrome c reductase and Steptoe nitrate reductase were identicalwhen digested with endoprotease lys-C but were distinctly different in one peptide when digested with Staphylococcus aureus endoprotease V8. These results provide evidence that nar 1 gene codes for the nitrate reductase polypeptide.

Molecular basis of bluetongue virus neutralization.

Molecular and serological analyses of bluetongue virus serotypes 10 and 11 and their intertype reassortants indicate that the viral RNA segment L2 codes for the serotype-specific antigen. Individual RNA segments of parental and reassortant viruses were characterized by oligonucleotide fingerprint analyses. Analyses of their virion polypeptides by Cleveland peptide mapping (Cleveland et al., J. Biol. Chem. 252:1102-1106, 1977) demonstrated that the L2 gene segregated colinearly with the viral P2 protein, implicating it as the antigen that is responsible for the viral serotype specificity.