Changes of lipo-melanosome membrane leakage versus pH, charge and composition

Melanoma Res. 1991 Aug-Sep;1(3):195-200.

Abstract

Liposome models of melanosomes (lipo-melanosomes) were used to investigate how phospholipid composition, charge and medium pH may affect the lipo-melanosome membrane permeability to active oxygen species or melanin synthesis intermediaries. Active oxygen accumulated only at pH 6.4 and was polarographically monitored using superoxide dismutase and/or catalase. Cholesterol appears to increase the O2- accumulation at pH 6.4 while incorporation of positive phospholipids within lipo-melanosomes results in the loss of latency with respect to tyrosinase substrate and intermediates of melanin synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalase / metabolism
  • Cholesterol / metabolism
  • Dihydroxyphenylalanine / metabolism
  • Glutathione / metabolism
  • Hydrogen-Ion Concentration
  • Liposomes / metabolism*
  • Membrane Lipids / metabolism
  • Monophenol Monooxygenase / metabolism*
  • Oxidation-Reduction
  • Oxygen / metabolism
  • Permeability
  • Phospholipids / metabolism
  • Superoxide Dismutase / metabolism

Substances

  • Liposomes
  • Membrane Lipids
  • Phospholipids
  • Dihydroxyphenylalanine
  • Cholesterol
  • Catalase
  • Monophenol Monooxygenase
  • Superoxide Dismutase
  • Glutathione
  • Oxygen