Steroid-protein interactions studied by fluorescence quenching

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Abstract

  • 1.

    1. Fluorescence quenching titration is a sensitive and rapid method for the study of steroid-protein molecular interactions. The procedure has been applied to systems containing androstane derivatives and proteins or aromatic amino acids.

  • 2.

    2. The results suggest that testosterone binding may alter bovine serum albumin conformation and that the measured binding capacity of this protein for testosterone is dependent on the protein concentration. High molar ratios of bound steroid to protein are obtained with dilute albumin solutions and may reflect the N-F transformations observed by others.

  • 3.

    3. In 6 M urea or higher the quenching of intrinsic serum albumin fluorescence by testosterone disappears. The reasons for the abolition of this steroid quenching by urea are discussed.

  • 4.

    4. The strong binding of androstane and androstane-17-one and the decreased binding of more polar steroids to albumin indicate the hydrophobic nature of the bonds involved. Binding of steroid to protein is modified by the presence and location of oxygen functions and double bonds.

References (43)

  • U. Westphal et al.

    J. Biol. Chem.

    (1959)
  • U. Westphal et al.

    J. Biol. Chem.

    (1962)
  • E.K. Oyakawa et al.

    Arch. Biochem. Biophys.

    (1958)
  • D. Abelson et al.

    Arch. Biochem. Biophys.

    (1960)
  • G.J. Chader et al.

    J. Biol. Chem.

    (1968)
  • S. Wang et al.

    J. Biol. Chem.

    (1963)
  • R.F. Steiner et al.

    J. Biol. Chem.

    (1966)
  • S.S. Lehrer

    Biochem. Biophys. Res. Commun.

    (1967)
  • S.F. Velick

    J. Biol. Chem.

    (1958)
  • G. Molinari et al.

    Arch. Biochem. Biophys.

    (1962)
  • G.F. Lata et al.

    Arch. Biochem. Biophys.

    (1965)
  • D.B. Wetlaufer et al.

    J. Biol. Chem.

    (1964)
  • W.J. Leonard et al.

    J. Biol. Chem.

    (1961)
  • W.K. Brunkhorst et al.

    Arch. Biochem. Biophys.

    (1965)
  • U. Westphal et al.

    J. Biol. Chem.

    (1958)
  • A. Munck et al.

    Biochim. Biophys. Acta

    (1957)
  • U. Westphal
  • F. Teale et al.

    Biochem. J.

    (1957)
  • G.F. Lata et al.
  • A. Berger et al.

    Bull. Res. Council Israel, Sect. A

    (1958)
  • H.A. McKenzie et al.

    Australian J. Chem.

    (1954)
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    Present address: Laboratory of Biophysical and Immunochemistry, Department of Chemistry, McGill University, Montreal, Quebec, Canada.

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