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Biomedical subjects

M A Clayton

Publications and source records attributed to M A Clayton.

4 recordsLinked to original sources
PubMed1995

Expression of a large, nontoxic fragment of botulinum neurotoxin serotype A and its use as an immunogen.

Using the polymerase chain reaction, a large fragment of botulinum toxin was placed in two expression systems, one designed to produce a fusion protein product and another designed to produce only the toxin fragment. Expression of the fragment in the latter system was inconsistent. Expression of the fusion protein was easily measurable by ELISA. Mice were vaccinated with crude fusion protein, then challenged with native toxin. Mice receiving two immunizations were partially protected from up to 1200 LD50, suggesting that this toxin fragment may be a good vaccine candidate to replace the currently used toxoid.

Animals↗
PubMed1995

Protective vaccination with a recombinant fragment of Clostridium botulinum neurotoxin serotype A expressed from a synthetic gene in Escherichia coli.

A completely synthetic gene encoding fragment C, a approximately 50-kDa fragment, of botulinum neurotoxin serotype A was constructed from oligonucleotides. The gene was expressed in Escherichia coli, and full-sized product was produced as judged by Western blot (immunoblot) analysis. Crude extracts of E. coli expressing the gene were used to vaccinate mice and evaluate their survival against challenge with active toxin. Mice given three subcutaneous vaccinations were protected against an intraperitoneal administration of 10(6) 50% lethal doses (ID50) of serotype A toxin. The same mice survived when challenged with 3 LD50 of botulinum toxin serotype E but died when challenged with 10 LD50 of serotype E or 3 LD50 of serotype B. Purified fragment C was compared with the botulinum toxoid vaccine in a vaccination and challenge study. Fragment C was as efficacious in protecting against challenge with active botulinum neurotoxin serotype A as the toxoid vaccine. This recombinant protein product has many properties that make it a good candidate for human use to protect against botulinum toxin.

Animals↗
PubMed1978

Control of Escherichia coli growth by CO2.

Escherichia coli B dependence on CO2 for growth was demonstrated. At suboptimal CO2 concentrations the rate of growth was controlled by CO2 concentration.

Bacterial Proteins↗