Premium
POST‐MORTEM GL YCOL YSIS IN OX SKELETAL MUSCLE: EFFECT OF ADDING NICOTINAMIDE‐ADENINE DINUCLEOTIDE TO DILUTED MINCE PREPARATIONS
Author(s) -
NEWBOLD R. P.,
SCOPES R. K.
Publication year - 1971
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1971.tb04027.x
Subject(s) - nad+ kinase , nicotinamide adenine dinucleotide , chemistry , biochemistry , dehydrogenase , nucleotide , phosphofructokinase , cofactor , nicotinamide , glycolysis , enzyme , adenine nucleotide , gene
— Samples of mince, prepared from ox sternomandibularis muscle about 75 min postmortem, were diluted with one volume of 0.16M potassium chloride containing 0, 50 or 100 mM potassium phosphate with or without 1 mg of nicotinamide‐adenine dinucleotide (NAD)/ml. Changes in pH and in the concentrations of glycolytic intermediates and the principal nucleotides were followed for about 6 hr after dilution. NAD was lost rapidly, its adenine moiety being converted to inosine nucleotide by the enzymes present. When the diluent did not contain inorganic phosphate (P i ) inclusion of NAD resulted in a somewhat faster loss of adenosine triphosphate (ATP), earlier cessation of glycolysis and higher ultimate pH. Inclusion of NAD in the preparations containing added P i led to a reduction in both phosphorylase and phosphofructokinase activity. It also prevented the accumulation of fructose diphosphate. This was the result of lowering the phosphofructokinase activity rather than of increasing the glyceraldehyde‐3‐phosphate dehydrogenase activity. Adenosine triphosphatase (ATPase) activity, after an initial period during which it was unaffected by inclusion of NAD, was greater in the preparations containing added P i and NAD than in the corresponding preparations without added NAD.