Effects of GPI-anchored TNAP on the dynamic structure of model membranes

Author(s)

Garcia, A. F. ^[1] ; Simao, A. M. S. ^[2] ; Bolean, M. ^[2] ; Hoylaerts, M. F. ^[3] ; Millan, J. L. ^[4] ; Ciancaglini, P. ^[2] ; Costa-Filho, A. J. ^[1]

Affiliation

^[1] Univ Sao Paulo, Lab Biofis Mol, Dept Fis, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[3] Univ Leuven, Ctr Mol & Vasc Biol, Leuven - Belgium

^[4] Sanford Burnham Prebys Med Discovery Inst, Sanford Childrens Hlth Res Ctr, La Jolla, CA - USA

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 17, n. 39, p. 26295-26301, 2015.
• Web of Science Citations: 3

Abstract

Tissue-nonspecific alkaline phosphatase (TNAP) plays a crucial role during skeletal mineralization, and TNAP deficiency leads to the soft bone disease hypophosphatasia. TNAP is anchored to the external surface of the plasma membranes by means of a GPI (glycosylphosphatidylinositol) anchor. Membrane-anchored and solubilized TNAP displays different kinetic properties against physiological substrates, indicating that membrane anchoring influences the enzyme function. Here, we used Electron Spin Resonance (ESR) measurements along with spin labeled phospholipids to probe the possible dynamic changes prompted by the interaction of GPI-anchored TNAP with model membranes. The goal was to systematically analyze the {[}SR data in terms of line shape changes and of alterations in parameters such as rotational diffusion rates and order parameters obtained from non-linear {[}east-squares simulations of the {[}SR spectra of probes incorporated into DPPC liposomes and proteoliposomes. Overall, the presence of TNAP increased the dynamics and decreased the ordering in the three distinct regions probed by the spin labeled lipids DOPTC (headgroup), and 5- and 16-PCSL (acyl chains). The largest change was observed for 16-PCSL, thus suggesting that GPI-anchored TNAP can give rise to long reaching modifications that could influence membrane processes halfway through the bilayer. (AU)

• FAPESP's process: 14/11941-3 - Are collagen and Annexin V responsible for the control in the biomineralization process?
• Grantee: Pietro Ciancaglini
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/00371-1 - Are the interactions between collagen and proteins/enzymes present in the matriz vesicles responsible for the control in the biomineralization process?
• Grantee: Maytê Bolean Correia
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/26088-1 - Tissue-nonspecific alkaline phosphatase (TNAP) from Homo sapiens and its membrane docking mechanism - a biophysical approach
• Grantee: Assuero Faria Garcia
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 10/17662-8 - Electron magnetic resonance in studies of structure, function and interactions of biologically-relevant molecules
• Grantee: Antonio José da Costa Filho
• Support Opportunities: Regular Research Grants