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Biomedical subjects

W R Hearn

Publications and source records attributed to W R Hearn.

6 recordsLinked to original sources

Separation of prodigiosenes and identification as prodigiosin syntrophic pigment from mutant pairs of Serratia marcescens.

Countercurrent distribution is capable of resolving mixtures of closely related prodigiosene pigments. Syntrophic pigment produced by several pairs of Serratia marcescens color mutants was identified as prodigiosin (2-methyl-3-amyl-6-methoxyprodigiosene) by countercurrent distribution, soda lime pyrolysis, and other techniques. The metabolic block of mutant strain H-462, derived from parent strain HY, was located between the blocks of mutant strains OF and WF, both derived from parent strain Nima.

Bacteriological Techniques

Specificity of a bacteriolytic enzyme from Pseudomonas aeruginosa.

A bacteriolytic enzyme isolated from shake-flask cultures of Pseudomonas aeruginosa and capable of lysing cells of Staphylococcus aureus was purified approximately 500-fold by passage through diethylaminoethyl cellulose and chromatography on carboxymethyl-cellulose. The purified enzyme was shown to act as an endopeptidase, cleaving the pentaglycine cross-bridges of the cell wall peptidoglycan at d-alanyl-glycine and glycyl-glycine linkages with the release of di-, tri-, and tetraglycine fragments. Release of NH(2)-alanine indicated weak N-acetylmuramyl-l-alanine amidase activity, but most of the residual peptide remained attached to the glycan. No hydrolysis of the glycan occurred. The lytic spectrum of the enzyme toward a variety of other cell walls of known peptidoglycan composition indicated relatively high specificity for peptidoglycans with polyglycine bridges.

Aminohydrolases