Phospholipid transfer proteins: Mechanism of action

Abstract

Phospholipid transfer proteins are generally localized in the cytosolic fraction of cells and are capable of catalyzing the flux of phospholipid molecules among membranes. Artificial membranes also participate in protein-catalyzed phospholipid movements. In this review the major phospholipid transfer proteins are discussed with respect to their phospholipid substrate specificity and the contributions of membrane physical properties to this process. The phenomenon of net transfer of phospholipids is described. The use of various kinetic approaches to the study of these catalysts is reviewed. A detailed consideration of the distinct phospholipid binding and membrane interaction domains of one phospholipid transfer protein is presented. Finally, some recent applications of phospholipid transfer proteins to the examination of membrane structure and function and further directions for the continued research activity with this class of proteins are summarized.

Lipid Traffic in Animal Cells

“…Biol. 1989.5:247-275 pholipid-rich vesicles has been reported to be responsible for the rapid plasma membrane growth during mitosis (Bluemink et al 1983) Blok et al 1971) or faster (Yaffe & Kennedy 1983).11 Candidates for mediating this equilibration, which according to the present view is not vesicular, are two transfer proteins that possess the capability to transport PC monomers across an aqueous barrier; one has a strict specificity for PC, the other is specifi c for PI and PC (reviewed in Helmkamp 1986). 12…”

Nonvesicular Lipid Transfer from the Endoplasmic Reticulum

“…Instead, LTPs use their lipid-transfer activity to modulate the lipid content of membranes according to their local membrane environment. The lipid type and its surface concentration as well as additional parameters including the lipid composition of the donor and acceptor membranes, their charge, curvature, size, and fluidity, influence lipid transport by LTPs (Helmkamp 1986;Nichols 1988;Gadella and Wirtz 1994). The membrane association and dissociation steps (donor and acceptor) mostly depend on physical parameters such as membrane charge, curvature, and size (Nichols 1988;Gadella and Wirtz 1994).…”

Isolation of a cDNA Clone for Spinach Lipid Transfer Protein and Evidence that the Protein Is Synthesized by the Secretory Pathway

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(10,12,29). Under conditions in which the donor membrane is actively engaged in lipid synthesis, plant lipid transfer proteins have also been shown to catalyze net transfer from the donor to acceptor membrane ( 17).

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“…Lipid transfer proteins, which have been isolated from animals, yeast, plants, and bacteria, are characterized by their ability to catalyze exchange of lipids between natural or artificial membranes in vitro (10,12,29). Under conditions in which the donor membrane is actively engaged in lipid synthesis, plant lipid transfer proteins have also been shown to catalyze net transfer from the donor to acceptor membrane ( 17).…”