R. Rogers Yocum

7-Nitrobenz-2-oxa-1,3-diazole (NBD)--phallacidin: synthesis of a fluorescent actin probe.

Abstract Phallacidin was labeled with the fluorophore, 4-chloro-7-nitrobenz-2-oxa-1,3-diazole, after a series of modifications. The complete purification and synthesis of intermediates are described. A simple laboratory procedure for production of the fluorescent toxin is outlined. The fluorescent phallacidin was used to stain plant and animal cellular actin. Because of the low molecular weight, high actin specificity and visible excitation profile of the conjugated toxin, fluorescent phallacidin, has proven useful in the fluorescence microscopic study of actin in vivo and in vitro.

Interaction of penicillin with its receptors in bacterial membranes

Abstract The details of the mechanism of action of penicillin are still being investigated actively. Recent studies have shown that penicillin and substrate acylate the same active site serine in cell wall carboxypeptidas. s-Lactamases probably evolved from cell wall biosynthetic enzymes.