Interactions of calcium binding proteins, parvalbumin and alpha-lactalbumin, with dipalmitoylphosphatidylcholine vesicles

Gen Physiol Biophys. 1988 Feb;7(1):95-107.

Abstract

Interactions of Ca2+ binding proteins, pike (Esox lucius) parvalbumins pI 4.2 and 5.0, and bovine and human alpha-lactalbumins, with dipalmitoylphosphatidylcholine vesicles were studied by means of scanning microcalorimetry and intrinsic tyrosine and tryptophan fluorescence methods. The interactions of pike parvalbumins are modulated by Ca2+ and Mg2+ binding to the protein and induce some changes in the physical properties of both the proteins and liposomes. Liposomes increased thermal stability of Ca2+-loaded parvalbumin and decreased thermal stability of both Mg2+-loaded and metal-free protein. The interaction of parvalbumin with liposomes affects the phase transition from gel to liquid-crystalline state in liposomes. Ca2+-loaded alpha-lactalbumin interacts with liposomes in its native state while the metal-free protein binds to the liposomes mainly in its thermally denatured state. The results of the microcalorimetric and spectrofluorometric studies are supported by data obtained by means of gel-chromatography on Sepharose 4B. It may be suggested that these metal-modulated interactions of Ca2+-binding proteins with membranes have some functional significance.

MeSH terms

  • 1,2-Dipalmitoylphosphatidylcholine*
  • Animals
  • Calcium / metabolism
  • Calcium-Binding Proteins / metabolism*
  • Calorimetry
  • Cattle
  • Humans
  • Lactalbumin / metabolism*
  • Lipid Bilayers*
  • Magnesium / metabolism
  • Muscle Proteins / metabolism*
  • Parvalbumins / metabolism*
  • Protein Binding
  • Salmonidae

Substances

  • Calcium-Binding Proteins
  • Lipid Bilayers
  • Muscle Proteins
  • Parvalbumins
  • 1,2-Dipalmitoylphosphatidylcholine
  • Lactalbumin
  • Magnesium
  • Calcium