First X-ray crystal structure and internal reference diffusion-ordered NMR spectroscopy study of the prototypical Posner reagent, MeCu(SPh)Li(THF)3.

Grow slow: The usual direct treatment of MeLi and CuSPh did not yield X-ray quality crystals of MeCu(SPh)Li. An indirect method starting from Me2CuLi⋅LiSPh and chalcone afforded the desired crystals by the slow reaction of the intermediate π-complex (see scheme). This strategy produced the first X-ray crystal structure of a Posner cuprate.

Single cell endocrinology: analysis of P-450scc activity by fluorescence detection methods.

A mechanism-based, fluorogenic probe for the cytochrome P-450scc (cholesterol side chain cleavage) enzyme, rate-limiting for the conversion of cholesterol to steroid hormones, is introduced and its application to the study of enzyme activity and regulation in single steroidogenic cells by several fluorescence detection methods is demonstrated. Reaction of the probe with P-450scc gives pregnenolone and the highly fluorescent resorufin anion. Spectroscopic changes in probe fluorescence, indicative of P-450scc activity, were monitored by steady-state fluorescence spectroscopy, flow cytometry, and microspectrofluorometry.

Glycation of calmodulin: chemistry and structural and functional consequences.

In the presence of Ca2+ and glucose, calmodulin incorporates 2.5 mol of glucose/mol of protein. In the absence of Ca2+, only 1.