The synthesis of succinate-dehydrogenase riboflavin.

Singer and Kearney"], in their early studies, recognized that the flavocoenzyme of mitochondria1 succinate dehydrogenase ("SD-flavin") [**I was a derivative of flavin-adenine-dinucleotide which was covalently bound to the protein. In cooperation with Dr. Singer's team [***I, we have attempted to elucidate the structure of this coenzyme. In the first preliminary communication I21, we concluded from the hyperfine structure of electron spin resonance (ESR) spectra of partially purified SD-riboflavin (obtained from SD-FADpeptide mixtures by total hydrolysis in 6 N HCl) that