The dependence of electrophoretic and spectroscopic properties of the pyruvate dehydrogenase complex on mono- and divalent ions.
The effects of various mono- and divalent ions on the pyruvate dehydrogenase complex (PDC) were investigated. To determine the radius of PDC under various conditions a two-dimensional agarose gel electrophoresis technique was used. The radius of PDC cross-linked with glutaraldehyde at ionic strength 0.04 M was calculated to be 22.0 +/- 0.1 nm. The presence of K+, Na+ or HPO4(2-) prevented changes in electromobility and of the calculated radius of PDC induced by alteration in ionic strength. The fluorescence emission spectra of PDC depended on the ionic strength and monovalent cations. The fluorescence intensity of PDC increased in the presence of 80 mM K+, and decreased in the presence of 80 mM Na+ with no shift in the emission maximum wavelength. Changes in the ionic strength to which PDC was exposed resulted in alteration of the UV absorption spectra in the 230 nm region. These alterations were prevented by HPO4(2-), whereas Na+ or K+ ions had no effect on the UV absorption spectrum of PDC.
Faculty of Biotechnology, University of Gdańsk, Poland.
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Pawełczyk
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Easom
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Olson
D004587:Electrophoresis, Agar Gel; D007477:Ions; D009994:Osmolar Concentration; D011768:Pyruvate Dehydrogenase Complex / Q000737:chemistry / Q000187:drug effects*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
D007477:Ions; D011768:Pyruvate Dehydrogenase Complex