IDENTIFICATION OF THE QUINONE COFACTOR IN A LYSYL OXIDASE FROM PICHIA-PASTORIS

A copper amine oxidase from Pichia pastor is is the only known non-mam malian lysyl oxidase [Tur, S.S. and Lerch, K. (1988) FEES Lett. 238, 7 4-76]. Recently, the cofactor in mammalian lysyl oxidase has been iden tified as a novel lysine tyrosylquinone moiety [Wang, S.X., Mure, M., Medzihradszky, K.F., Burlingame, A.L., Brown, D.E., Dooley, D.M., Smit h, A.J., Kagan, H.M. and Klinman, J.P. (1996) Science 273, 1078-1084]. In order to identify the cofactor in P. pastoris lysyl oxidase, me ha ve isolated the phenylhydrazone-derivative of the active-site peptide. This peptide has the active-site sequence conserved among topa quinon e containing amine oxidases. The resonance Raman spectra of the phenyl hydrazone derivatives of the enzyme, active-site peptide, and a topa q uinone model compound are essentially identical. Collectively, these r esults establish that P. pastoris lysyl oxidase is a topa quinone enzy me.