GLTP-fold interaction with planar phosphatidylcholine surfaces is synergistically stimulated by phosphatidic acid and phosphatidylethanolamine[S]

Xiuhong Zhai; William E. Momsen; Dmitry A. Malakhov; Ivan A. Boldyrev; Maureen M. Momsen; Julian G. Molotkovsky; Howard L. Brockman; Rhoderick E. Brown

Journal of Lipid Research (Apr 2013)

GLTP-fold interaction with planar phosphatidylcholine surfaces is synergistically stimulated by phosphatidic acid and phosphatidylethanolamine[S]

Xiuhong Zhai,
William E. Momsen,
Dmitry A. Malakhov,
Ivan A. Boldyrev,
Maureen M. Momsen,
Julian G. Molotkovsky,
Howard L. Brockman,
Rhoderick E. Brown

Affiliations

Xiuhong Zhai: The Hormel Institute, University of Minnesota, Austin, MN; and
William E. Momsen: The Hormel Institute, University of Minnesota, Austin, MN; and
Dmitry A. Malakhov: The Hormel Institute, University of Minnesota, Austin, MN; and
Ivan A. Boldyrev: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
Maureen M. Momsen: The Hormel Institute, University of Minnesota, Austin, MN; and
Julian G. Molotkovsky: To whom correspondence should be addressed (J.G.M.) [email protected]; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia; To whom correspondence should be addressed. (R.E.B.) [email protected]
Howard L. Brockman: To whom correspondence should be addressed. (H.L.B.) [email protected]; The Hormel Institute, University of Minnesota, Austin, MN; and; To whom correspondence should be addressed. (R.E.B.) [email protected]
Rhoderick E. Brown: To whom correspondence should be addressed. (R.E.B.) [email protected]; The Hormel Institute, University of Minnesota, Austin, MN; and; To whom correspondence should be addressed. (R.E.B.) [email protected]

Journal volume & issue: Vol. 54, no. 4
pp. 1103 – 1113

Abstract

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Among amphitropic proteins, human glycolipid transfer protein (GLTP) forms a structurally-unique fold that translocates on/off membranes to specifically transfer glycolipids. Phosphatidylcholine (PC) bilayers with curvature-induced packing stress stimulate much faster glycolipid intervesicular transfer than nonstressed PC bilayers raising questions about planar cytosol-facing biomembranes being viable sites for GLTP interaction. Herein, GLTP-mediated desorption kinetics of fluorescent glycolipid (tetramethyl-boron dipyrromethene (BODIPY)-label) from lipid monolayers are assessed using a novel microfluidics-based surface balance that monitors lipid lateral packing while simultaneously acquiring surface fluorescence data. At biomembrane-like packing (30–35 mN/m), GLTP uptake of BODIPY-glycolipid from POPC monolayers was nearly nonexistent but could be induced by reducing surface pressure to mirror packing in curvature-stressed bilayers. In contrast, 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE) matrices supported robust BODIPY-glycolipid uptake by GLTP at both high and low surface pressures. Unexpectedly, negatively-charged cytosol-facing lipids, i.e., phosphatidic acid and phosphatidylserine, also supported BODIPY-glycolipid uptake by GLTP at high surface pressure. Remarkably, including both 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (5 mol%) and POPE (15 mol%) in POPC synergistically activated GLTP at high surface pressure. Our study shows that matrix lipid headgroup composition, rather than molecular packing per se, is a key regulator of GLTP-fold function while demonstrating the novel capabilities of the microfluidics-based film balance for investigating protein-membrane interfacial interactions.

Published in Journal of Lipid Research

ISSN: 0022-2275 (Print); 1539-7262 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Science: Chemistry: Organic chemistry: Biochemistry
Website: https://www.journals.elsevier.com/journal-of-lipid-research

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