Detail of "42189-56-0"

Reference

Spectroscopic probes for acetylcholine receptor function

Spectroscopic probes for acetylcholine receptor function. Clarke, Jeffrey Homer (Virginia Commonw. Univ., Richmond, VA, USA). 135 pp. Avail. Univ.In this article, certain chemicals are used. Some of their cas registry numbers are 69489-90-3 and 42189-56-0 Microfilms Int., Order No. DA8623117 From: Diss. Abstr. Int. B 1987, 47(7), 2879 (English) 1986. DOCUMENT TYPE: Dissertation CA Section: 6 (General Biochemistry) Section cross-reference(s): 9 Abstract Unavailable .

Conformational changes of 30S ribosomes measured by intrinsic and extrinsic fluorescence

Conformational changes of 30S ribosomes measured by intrinsic and extrinsic fluorescence. Spitnik-Elson, Pnina; Schechter, Nisson; Abramovitz, Renne; Elson, David (Biochem. Dep.In this study， 42189-56-0 and 73-22-3 are also used., Weizmann Inst. Sci., Rehovot, Israel). Biochemistry, 15(24), 5246-53 (English) 1976. CODEN: BICHAW. DOCUMENT TYPE: Journal CA Section: 6 (General Biochemistry) The intrinsic tryptophan fluorescence and the fluorescence of N-(3-pyrene)maleimide, a covalently bound SH-specific extrinsic probe, were used to study the conformation of the 30 S ribosomal subunit of Escherichia coli. The tryptophan fluorescence spectrum of the free ribosomal proteins was shifted to shorter wavelengths than that of free tryptophan. When the proteins were incorporated into the organized structure of the ribosome, there was a small addnl. blue shift and the emission band became narrower. In 6M urea, the spectrum of the proteins, whether free or in the ribosome, became identical with that of the amino acid, reflecting exposure of previously shielded tryptophan residues. When Mg-depleted ribosomes were unfolded at low-ionic strength, the tryptophan fluorescence spectrum changed, although CD showed no change in .alpha.-helix content of the proteins. Intrinsic and extrinsic fluorescence were both sensitive to a limited and fully reversible transition that occurred when ribosomes were incubated under conditions that increased their activity in vitro. This suggested that both probes may be of use in monitoring conformational changes that occur under conditions consistent with activity. The kinetics of the concurrent changes in extrinsic fluorescence and aminoacyl-tRNA binding activity were compared. Conditions are described for labeling ribosomes with N-(3-pyrene)maleimide without impairing their activity. .