Premium
Quinoproteins
Author(s) -
McIntire William S.
Publication year - 1994
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.8.8.8181669
Subject(s) - pyrroloquinoline quinone , chemistry , amine gas treating , quinone , cofactor , enzyme , amine oxidase , stereochemistry , biochemistry , residue (chemistry) , alcohol dehydrogenase , tryptophan , methanol dehydrogenase , organic chemistry , amino acid
As used today, the word quinoprotein defines three distinct groups of enzymes. Before 1979, the structures of the essential, quinonoid oxidation‐reduction cofactors were a mystery for all these enzymes. The first proteins proven to harbor this type prosthetic group are those with noncovalently bound pyrroloquinoline quinone (PQQ). PQQ‐containing enzymes can be described as alcohol dehydrogenases, with the exception of a single protein, which is an amine dehydrogenase. More recently, it was discovered that copper‐containing amine oxidases contain 6‐hydroxydopa quinone, also known as topa quinone (TQ), whereas certain bacterial amine dehydrogenases require 2',4‐bitryptophan‐6,7‐dione (tryptophan tryptophylquinone, TTQ) for activity. These latter two quinones are formed, by unknown processes, from a specific tyrosyl residue for the amine oxidases, and from two widely separate tryptophyl residues in the polypeptide of the amine dehydrogenases.—McIntire, W. S. Quinoproteins. FASEB J. 8: 513‐521; 1994.