Open AccessImmunologic evidence that the gene for L-gulono-gamma-lactone oxidase is not expressed in animals subject to scurvy.
Author(s) -
Morimitsu Nishikimi,
Sidney Udenfriend
Publication year - 1976
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.73.6.2066
Subject(s) - guinea pig , oxidase test , biochemistry , microsome , ascorbic acid , enzyme , antiserum , biology , scurvy , microbiology and biotechnology , chemistry , antibody , endocrinology , immunology , vitamin c , food science
L-Gulono-gamma-lactone oxidase (L-gulono-gamma-lactone:oxygen 2-oxidoreductase, EC 1.1.3.8) is the enzyme that catalyzes the terminal step of L-ascorbic acid biosynthesis in mammalian liver. The absence of the oxidase activity in primates and guinea pigs is the reason why these animals are subject to scurvy, which must be considered an inborn error of metabolism. Attempts were made to determine if a protein immunologically crossreactive with L-gulono-gamma-lactone oxidase is present in these animals. Detergent-solubilized microsomal preparations from guinea pig and African green monkey liver did not precipitate the antisera directed to either rat or goat enzyme, nor did any of the other cell fractions obtained from guinea pig liver react with either antiserum. No crossreactive protein was detectable in guinea pig microsomes even with the sensitive procedure or micro-complement fixation. On the other hand, extracts of all 10 other mammalian (4 orders) liver microsomes tested were shown to contain L-gulono-gamma-lactone oxidase activity that did crossreact with antibodies to the rat and goat enzymes. One explanation of these findings is that, in the guinea pig, and perhaps in primates too, the structural gene for L-gulono-gamma-lactone oxidase is not expressed.