Pawełczyk T, Easom R A, Olson M S
Faculty of Biotechnology, University of Gdańsk, Poland.
Acta Biochim Pol. 1994;41(1):63-72.
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.
研究了各种单价和二价离子对丙酮酸脱氢酶复合体（PDC）的影响。为了确定在各种条件下PDC的半径，使用了二维琼脂糖凝胶电泳技术。计算得出，在离子强度为0.04 M时，与戊二醛交联的PDC半径为22.0±0.1 nm。K⁺、Na⁺或HPO₄²⁻的存在可防止因离子强度改变而引起的PDC电泳迁移率和计算半径的变化。PDC的荧光发射光谱取决于离子强度和单价阳离子。在80 mM K⁺存在下，PDC的荧光强度增加，而在80 mM Na⁺存在下荧光强度降低，发射最大波长无位移。PDC所暴露的离子强度变化导致230 nm区域紫外吸收光谱的改变。HPO₄²⁻可防止这些改变，而Na⁺或K⁺离子对PDC的紫外吸收光谱无影响。
