@conference{
author = "Radibratović, Milica and Al-Hanish, Ayah and Minić, Simeon and Radomirović, Mirjana Ž. and Milčić, Miloš and Stanić-Vučinić, Dragana and Ćirković-Veličković, Tanja",
year = "2018",
abstract = "α-Lactalbumin (ALA) is a small, acidic, Ca2+-binding protein that might constitute up to 20% of whey protein. ALA has several partially folded intermediate states. It is very attractive for studies of the properties and structure of intermediate molten globule-like states since at acidic pH and in the apo-state at elevated temperatures ALA is the classic ‘molten globule’.The aim of our study was to examine if epi-gallo-catechin-3-gallate (EGCG) binds to ALA in its Ca-depleted (apo-ALA) and less ordered states. Moreover we examined if the polyphenol binding can stabilize protein structure. The experimental investigation of EGCG binding and protein’s stability were supported by molecular dynamics data.Green tea catechin binds to apo-ALA in neutral and acidic conditions. Binding affinity determined by intrinsic fluorescence quenching is of a similar magnitude as to the holo form of the protein. The complex of EGCG and ALA at neutral conditions is more stable to thermal denaturation then protein alone. The stabilizing effect is more pronounced for apo-ALA than for the holo-ALA.The docking analysis and molecular dynamic simulation (MDS) showed that EGCG binds to apoALA at the same site as to holoALA, in the hydrophobic pocket at the entrance of cleft between α and β subdomains, remaining bound during MDS. Ca2+ removal results in decreased conformational stability of ALA, where local destabilization of Ca2+-binding region propagates to cleft, with its slight opening. EGCG binding to apo-ALA increases stability of ALA by reverting of conformation and stability of disturbed Ca2+-binding region, which is transmitted to cleft, resulting in rejoining of α and β subdomains and slight cleft closing by the same mechanism. EGCG binding could retard transition of apo-ALA to less ordered states under conditions favoring its formation.Therefore, non-covalent binding of EGCG can stabilize structural fold of calcium-depleted ALA.",
publisher = "Univerzitet u Beogradu",
journal = "UNIFOOD Conference, Belgrade, Serbia, 5th–6th October, 2018. In: UNIFOOD Conference - Programme and Book of Abstracts",
title = "Stabilization of apo-alpha-lactalbumin by binding of epigallocatechin-3-gallate: experimental and molecular dynamics study",
pages = "268-268",
url = "https://hdl.handle.net/21.15107/rcub_cer_7462"
}