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Biomedical subjects

B J Rawlings

Publications and source records attributed to B J Rawlings.

10 recordsLinked to original sources
PubMed1999

Quantitative measurement of long range nuclear Overhauser enhancement.

Measurement of nuclear Overhauser enhancement is one of the mainstays of structural studies of molecules in solution. Measurements, particularly over long distances, are often compromised by spin diffusion. A robust and accurate method for measuring nuclear Overhauser enhancements that are largely free of spin diffusion effects is presented. The effects of using imperfect radiofrequency pulses are considered and experimental data are presented for Amphotericin B.

Magnetic Resonance Spectroscopy↗
PubMed1991

An acyl-carrier-protein-thioesterase domain from the 6-deoxyerythronolide B synthase of Saccharopolyspora erythraea. High-level production, purification and characterisation in Escherichia coli.

The C-terminal region of a multifunctional polypeptide from the 6-deoxyerythronolide B synthase of Saccharopolyspora erythraea is predicted to contain an acyl carrier protein and a thioesterase or acyltransferase activity [Cortes, J., Haydock, S. F., Roberts, G. A., Bevitt, D. J. & Leadlay, P. F. (1990) Nature 348, 176-178]. Site-directed mutagenesis by means of the polymerase chain reaction was used to construct an efficient pT7-based expression plasmid for this domain. The recently developed technique of electrospray mass spectrometry was used to demonstrate that the purified protein had not been post-translationally modified by attachment of a 4'-phosphopantetheine group. However, treatment with the serine proteinase inhibitor phenylmethylsulphonyl fluoride led to highly selective labelling of the predicted active site of the thioesterase or acyltransferase.

Amino Acid Sequence↗
PubMed1989

Production of new polyene antibiotics by Streptomyces cellulosae after addition of ethyl (Z)-16-phenylhexadec-9-enoate.

Ethyl (Z)-16-phenylhexadec-9-enoate (3), an analog of ethyl oleate (2), was synthesized and added to cultures of Streptomyces cellulosae ATCC 12625 which normally produce fungichromin (1) as the principal polyene antibiotic. These cultures showed drastic reduction of fungichromin biosynthesis but afforded four new polyene antibiotics with a truncated four carbon side chain which are designated as isochainin (11) (an isomer of chainin (10], 14-hydroxyisochainin (12), 1'-hydroxyisochainin (13), and 1',14-dihydroxyisochainin (14). The close correspondence of 13C NMR chemical shifts between these compounds and fungichromin suggests that the stereochemistry at every site is exactly analogous.

Anti-Bacterial Agents↗