DIAMINE OXIDASE FROM LENS ESCULENTA SEEDLINGS: PURIFICATION AND PROPERTIES

Article abstract of DOI:10.1016/0031-9422(83)80004-1

A diamine oxidase (DAO) (EC 1.4.3.6) has been purified to homogeneity from lentil seedlings.The purified protein has a MW of 154000 and is composed of two apparently identical subunits.It contains two Cu(2+) atoms and one carbonyl-like group per mol.The purified enzyme is pink-red in concentrated solution and shows a broad, well-defined, absorption band in the visible region centered at 498 nm.The ESR spectrum is typical of Cu(2+) in a tetragonal symmetry.The enzyme oxidizes only aliphatic diamines and spermidine with formation of the corresponding aldehydes, hydrogen peroxide and ammonia.Putrescine and cadaverine are oxidized most rapidly and the oxidation rate decreases when longer diamines are tested. - Key Word Index - Lens esculenta; Leguminosae; lentil seedlings; copper protein; diamine oxidase.