Role of a Luciferin-Binding Protein in the Circadian Bioluminescent Reaction of Gonyaulax Polyedra

J Biol Chem. 1989 Jul 15;264(20):11822-6.

Abstract

A luciferin-binding protein (LBP), which binds and protects from autoxidation the substrate of the circadian bioluminescent reaction of Gonyaulax polyedra, has been purified to near homogeneity. The purified protein is a dimer with two identical 72-kDa subunits, and an isoelectric point of 6.7. LBP is a major component of the cells, comprising about 1% of the total protein during the night phase, but drops to only about 0.1% during the day. The luciferin is protected from autoxidation by binding to LBP, and one luciferin is bound per dimer at alkaline pH (Ka approximately 5 x 10(7) M-1). The protein undergoes a conformational change with release of luciferin at pH values below 7, concurrent with an activation of Gonyaulax luciferase. LBP thus has a dual role in the circadian bioluminescent system.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Carrier Proteins / isolation & purification
  • Carrier Proteins / metabolism*
  • Chromatography, Gel
  • Circadian Rhythm*
  • Dinoflagellida / enzymology*
  • Electrophoresis, Polyacrylamide Gel
  • Firefly Luciferin / metabolism*
  • Hydrogen-Ion Concentration
  • Kinetics
  • Luciferases / metabolism
  • Luminescent Measurements*

Substances

  • Carrier Proteins
  • Firefly Luciferin
  • Luciferases