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P D Bernard

Publications and source records attributed to P D Bernard.

At least 19 recordsLinked to original sources
PubMed1980

Ligand interactions of diphtheria toxin. I. Binding and hydrolysis of NAD.

Prior studies showed that diphtheria toxin could be separated into ATP-binding and nonbinding fractions (Fractions II and I, respectively) by affinity chromatography on ATP-Sepharose (Lory, S., and Collier, R. J. (1980) Proc. Natl. Acad. Sci. U. S. A. 77, 267-271). Here we show that the two fractions also differ in their interactions with NAD. Fraction II bound a single molecule of NAD (Kd about 9 microM) as assayed by flow dialysis or fluorescence quenching and catalyzed both NAD-glycohydrolase and auto-ADP-ribosylation reactions. Fraction I was deficient in NAD-binding and NAD-related reactions. The ratio of the two fractions vried widely among toxin preparations and was independent of the proportion of toxin in the nicked state. Properties of th NAD site on Fraction II were similar to, but not identical with, those of the corresponding site on free Fragment A.

Binding Sites↗
PubMed1977

Classification of Bacillus subtilis flagellins.

Purified flagellins derived from 16 strains of Bacillus subtilis were classified into at least five distinct groups on the basis of their reaction with antiflagellar filament antibody and antiflagellin antibody. This classification was in good accord with that derived independently on the basis of amino acid analyses of the flagellins. Flagellar antigenicity appears to provide a useful typological character in classifying B. subtilis strains.

Amino Acids↗
PubMed1972

Effect of proteolytic enzymes on bacterial flagella.

Sheared flagella of Salmonella typhimurium strains SL 870 (Nml(+)Fla(+)) and SL 871 (Nml(-)Fla(+)) were found to be susceptible to proteolytic digestion by trypsin, chymotrypsin, and Pronase. The rate of tryptic digestion was similar for the epsilon-N-methyllysine-containing and the nonmethylated flagella. Thin fibers, which appeared to originate from only one end of the flagellar filament, were formed upon trypsin digestion. The fibers were not dissociated at extremes of pH or upon heating. The amino acid composition of the purified fibers was very different from that of intact Salmonella flagellin, and the fibers did not cross-react with antiflagellin or antiflagellar antiserum. The possible significance of these findings is discussed in relation to the flagellar structure.

Amino Acids↗