We have studied the stoichiometry of the binding of the long alpha-neurotoxins from the venom of Dendroaspis viridis (alpha-dendrotoxin) and Naja naja siamensis (alpha-cobratoxin) to the membrane-bound acetylcholine receptor (AcChoR) from Torpedo californica electric organ. The number of toxin molecules bound to one AcChoR molecule was determined by simultaneous-quantitative gas-phase microsequ...

Antisera AS/6 and 7, raised against a synthetic peptide KENLKDCGLF corresponding to the carboxyl-terminal decapeptide of transducin-alpha, react on immunoblots with purified transducin-alpha and with proteins of 40-41 kDa in all tissues tested. The latter represent one or more forms of Gi alpha but not Go alpha, since a synthetic peptide, KNNLKDCGLF, corresponding to the carboxyl-terminal decap...

Previous studies on the electrophoretic migration of the components of crude staphylococcal toxin (1) led to an attempt to isolate the staphylococcal alpha hemolysin by these methods. The isolation of a homogeneous toxin which possessed alpha hemolytic, dermonecrotic, lethal, and leucocidal activities would provide strong direct support for the "unitarian" theory, which holds that these four ac...

Alpha-toxin is a major virulence factor in Staphylococcus aureus keratitis. Active or passive immunization with alpha-toxin toxoid could protect against corneal damage. Results show that either form of immunization did not kill bacteria but did significantly protect against corneal pathology, especially epithelial erosion.

Photoreactive derivatives of alpha- and beta-scorpion toxins have been used to analyze the subunit composition of Na+ channels in rat brain. In synaptosomes, both types of toxins preferentially labeled (greater than 85%) a component of 34,000 Da and, at a lower level, another component of 300,000 Da. Reduction of disulfide bridges shifted this latter band from 300,000 Da to 272,000 Da but did n...

Ontogeny of trimeric GTP-binding regulatory proteins (G-proteins) and their subunits in rabbit liver during neonatal development was studied, by using bacterial-toxin-catalysed ADP-ribosylation of membrane proteins, immunoblot analysis to quantify the alpha-subunit (alpha s and alpha i) of stimulatory (Gs) and inhibitory (Gi) G-protein and the beta-subunit, and reconstitution assay with cyc- me...

PURPOSE To investigate the corneal virulence of toxin-deficient mutants of Staphylococcus aureus in young and aged mice in a topical inoculation model of keratitis. METHODS Corneas of young and aged A/J mice were scarified and topically inoculated with a log phase S. aureus parent strain (8325-4), an alpha-toxin-deficient mutant (DU1090), or an Agr-defective mutant (ISP546) deficient in produ...

In this research a molecular method based on polymerase chain reaction for typing of Clostridium perfringens was developed and toxin genotypes of 64 isolates from sheep and goats in Iran were determined. The PCR assays were developed for detection of alpha (cpa), beta (cpb) and epsilon (etx) toxin genes, allowing classification of the isolates into genotypes A B, C and D. The field isolates ...

G-proteins are membrane-bound signal transduction proteins which couple extracellular receptor signals to various effectors. This study examines the expression and the function of G-proteins (alpha i, alpha s, alpha q, and alpha o) in experimental intimal hyperplasia. Vein bypass grafts were placed in 30 New Zealand White rabbits and were harvested after 28 d. The contralateral jugular veins se...