Native and guanidine hydrochloride-denatured pig heart mitochondrial malate dehydrogenase have fluorescence and phosphorescence emission spectra resembling tyrosine but not that of tryptophan. Furthermore, amino acid analysis of acid and alkaline hydrolysates of the pure enzyme, designed to detect 0.15 tryptophan residues or more per subunit, failed to show detectable quantities. It is confirmed that the enzyme lacks tryptophan and this amino acid can have no function in the catalytic mechanism.
ASJC Scopus subject areas
- Molecular Biology