Structural characterization of hydroperoxide lyase in dodecyl maltoside by using circular dichroism
I Panagakou1, E Touloupakis, D F Ghanotakis
1Department of Chemistry, University of Crete, P.O. Box 2208, 71003, Voutes-Heraklion, Greece.
Abstract:
Fatty acid hydroperoxide lyase (HPL) is a membrane protein, member of the lipoxygenase pathway, which holds a central role in plant defense. Green bell pepper fatty acid hydroperoxide lyase, overexpressed in Escherichia coli, was purified and solubilized in two different non ionic detergents, Triton X-100 and dodecyl maltoside (DM). DM is considered to be more useful compared to Triton X-100, as it allows characterization of the protein with spectroscopic techniques, for which Triton X-100 was inapplicable. Circular dichroism demonstrated that HPL's secondary structure in DM consists of 13.53 % α-helix, 32.73 % β-sheet, 21.76 % turn and 31.13 % unordered.
Related Concept Videos
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Preparation of Diols and Pinacol Rearrangement
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.


