Binding of51Cr to human erythrocytes

Radioactive chromium accumulated in human erythrocytes exists in two forms: one bound to macromolecules, e.g., hemoglobin, and one in a low molecular weight form. Both forms are released from cells either spontaneously or as a result of toxic induction.     

Characterisation of HlyC and mechanism of activation and secretion of haemolysin from E. coli 2001

In this paper the DNA sequence of the cloned hlyC gene from E. coli 2001 is presented. The gene encodes a protein of 20 kDa which is able to activate the 107 kDa polypeptide encoded by hlyA. This gives rise to a haemolytically active protein which differs from the inactive form in stability and by its migration when analysed by polyacrylamide gel electrophoresis under non-denaturing conditions. We also show that the inactive form is secreted in the presence of the transport functions hlyB and hlyD. This result rules out any role for the hlyC gene product in the transport of HlyA across the inner membrane.     

Improved purification and characterization of the OXA-2 beta-lactamase.

An improved and scaled-up procedure has been developed for purifying the OXA-2 plasmid-mediated beta-lactamase. This has enabled us to improve the characterization of this enzyme, including a revised determination of its amino acid composition and the sequence of the N-terminal region of the protein.