Ubiquinone binding protein used for determination of coenzyme Q

• Published in: Analytical biochemistry Vol. 320; no. 1; pp. 125 - 128
• Main Authors: Hagerman, Ruth A, Willis, Richard A, Hagerman, Ann E
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2003
• Subjects: Amino Acid Sequence; Animals; Binding, Competitive; Carrier Proteins - metabolism; CoQ assays; CoQ binding protein; Molecular Sequence Data; Peptides - analysis; Peptides - chemistry; Saccharomyces cerevisiae; Spectrophotometry; Ubiquinone; Ubiquinone - analysis; Ubiquinone - metabolism; CoQ assays; Ubiquinone; CoQ binding protein
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/S0003-2697(03)00345-2

The conventional method of assaying for the ubiquinone (CoQ) content of biological samples is to partition CoQ into an organic phase and separate it from contaminants by high-performance liquid chromatography (HPLC). HPLC is an accurate method of quantifying CoQ content but is not ideal for routine clinical analyses. This paper describes the development of a rapid method for assaying the CoQ content of biological samples based on the binding of CoQ to a CoQ binding peptide. The 14-amino acid binding peptide was chemically synthesized, and conditions for immobilizing the peptide on microfuge tubes were established. CoQ could be selectively bound to the immobilized peptide, eluted, and determined spectrophotometrically. Limits of detection for the method were 0.25 to 5 nmol CoQ. To test biological samples, CoQ was isolated from cultures of Saccharomyces cerevisiae grown in oleic acid medium. The recovery of CoQ samples using the binding assay ranged from 99 to 102% of the values obtained with HPLC. The assay described here provides an inexpensive, rapid method for determining the CoQ content of large numbers of biological samples in a variety of laboratory settings.