Effect of pH and calcium ions on the optimization of the incorporation of annexin A5 into liposomes

• Grant number: 17/25475-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): February 01, 2018
• Effective date (End): December 31, 2019
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Pietro Ciancaglini
• Grantee: Luiz Henrique da Silva Andrilli
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The biomineralization process consist on accumulation of minerals constituted mostly of ions of calcium and phosphate that form a calcium phosphate sault, whose structure is transform into hydroxyapatite. This process is mediate by osteoblasts, that are responsible for beginning of biomineralization process, mediated for release of matrix vesicles (MV's). These vesicles arise by budding of cells surface and are secreted at the specific spot in the beginning of biomineralization on the matrix of bone tissue. MV's contains high concentration of ions 2 mM Ca2+ and inorganic phosphate (Pi), providing a suitable microenvironment for the initial formation and propagation of the hydroxyapatite crystals. In this work a special attention should be given to some proteins present on MV's: Annexin V (AnxA5). Such proteins regulate the formation of calcium phosphate crystals, thus acting directly on the process of bone mineralization. Among the annexins, specifically AnxA5, a ~35 kDa protein, is responsible for the formation of calcium channels through association of this protein with both the outer and the inner face of the MV's membrane. The annexins are also responsible for cell membrane disorganization, which in turn results in the process of apoptosis. We intend to study, in this CI project, specifically the effect of pH and calcium ions on the process of incorporation of AnxA5. For this, the method for obtaining the proteoliposomes vesicular systems will be optimized and subsequently to study how these protein/protein and protein/lipid regulate and modulate the mineralization process. With these proteoliposomes we will be closer in MV's mimetic systems and we will able mimic their actions on the biomineralization. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PASQUARELLI, ALBERTO; SILVA ANDRILLI, LUIZ HENRIQUE; BOLEAN, MAYTE; FERREIRA, CLAUDIO REIS; EUFRASIO CRUZ, MARCOS ANTONIO; DE OLIVEIRA, FLAVIA AMADEU; RAMOS, ANA PAULA; MILLAN, JOSE LUIS; BOTTINI, MASSIMO; CIANCAGLINI, PIETRO. Ultrasensitive Diamond Microelectrode Application in the Detection of Ca2+ Transport by AnnexinA5-Containing Nanostructured Liposomes. BIOSENSORS-BASEL, v. 12, n. 7, p. 15-pg., 2022-07-01. (21/13140-1, 19/08568-2, 17/25475-2)