THE FLUOROMETRIC MEASUREMENT OF PYRIDINE NUCLEOTIDES

The fluorometric measurement of pyridine nucleotides.

Measurement of DPNH’ or TPNH by absorption at 344 rnp has been a standard procedure for many years and has been used to study innumerable enzyme reactions. In spite of the proved value of this calorimetric method, there may be advantages in fluorometric methods for the pyridine nucleotides. First, it has been found practicable with a fluorometer to determine separately oxidized and reduced pyri...

The measurement of pyridine nucleotides by enzymatic cycling.

In 1935 Negelein and Haas described a method for the determination of glucose 6-phosphate dehydrogenase activity based on measurement of the rate of reduced triphosphopyridine nucleotide formation from triphosphopyridine nucleotide (1). Since that time innumerable enzymes and substrates have been measured by the appearance or disappearance of reduced diphosphopyridine nucleotide or reduced trip...

The stability of pyridine nucleotides.

Diphosphopyridine nucleotide and triphosphopyridine nucleotide when used in appropriate enzyme systems become exceedingly useful reagents for the measurement of almost any biochemical substance. A companion paper describes procedures for measuring each of the pyridine nucleotides, whether in the oxidized or reduced form, at concentrations as low as 1O-g M and in amounts as small as lo-l5 moles ...

Fluorometric Measurement of Pyridine Nucleotide Reduction in the Giant Axon of the Squid

By monitoring the fluorescence of the isolated giant axon of the squid Loligo pealei, it was possible to follow changes in its oxidation-reduction state as caused by the action of anoxia, cyanide, Amytal, and azide. The response to oxygen depletion was very rapid, the NAD within the axon being 90% reduced within 1-2 min. Cyanide and Amytal gave essentially similar results, although somewhat lon...

Pyridine nucleotides in erythrocyte metabolism.