Covalently Bound Flavin in <scp>d</scp>‐6‐Hydroxynicotine Oxidase from <i>Arthrobacter oxidans</i>

Abstract

d ‐6‐Hydroxynicotine oxidase from Arthrobacter oxidans was previously shown to contain FAD covalently bound to the N‐3 of a histidyl residue of the apoprotein via the 8α‐methylene group of the flavin nucleus. For elucidating the structure around the flavin centre a tryptic‐chymotryptic FAD‐peptide from d ‐6‐hydroxynicotine oxidase was isolated and purified. The amino acid sequence of this FAD‐peptide was found to be Ser‐Gly‐Gly‐Asn‐Asn‐Pro‐Asp‐His‐Tyr‐(Gln‐Pro)‐Ala.