Investigating Enzyme Active-Site Geometry and Stereoselectivity in an Undergraduate Biochemistry Lab
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Saeed Roschdi [1] ; Theodore J. Gries [1]
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[1] Beloit College
Beloit College
City of Beloit, Estados Unidos
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 94, Nº 8, 2017, págs. 1098-1101
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
The three-dimensional nature of interactions between enzymes and their substrates often leads to exacting spatial binding orientations and stereoselectivity in chemical catalysis. Dehydrogenases that use NAD+ as a redox cofactor tend to show stereospecificity in transferring a hydride to the C4 of the nicotinamide moiety via either the re or the si face. The stereospecificity of this hydride transfer, which results in a prochiral C4 in the reduced NADH, may be determined using deuterated substrates and 1H NMR spectroscopy. A biochemistry lab activity that combines analysis of the intermolecular interactions and spatial orientation between substrate, cofactor, and enzyme from a recent crystal structure of yeast alcohol dehydrogenase with improved in situ single-tube reaction conditions for elucidating the prochiral specificity of yeast alcohol dehydrogenase through 1H NMR spectra analysis is presented.
