Preparation of Amyloidogenic Aggregates from EF-Hand β-Parvalbumin and S100 Proteins
Proteins containing EF-hand helix-loop-helix-binding motifs play essential roles in calcium homeostasis and signaling pathways. These proteins have considerable structural and functional diversity by virtue of their cation-binding properties, and occur as either Ca2+-bound or Ca2+-free states with distinct aggregation propensities. That is the case among β-parvalbumins and S100 proteins, which under certain conditions undergo Ca2+-dependent self-assembly reactions with the formation of oligomers, amyloid-type aggregates and fibrils. These phenomena may be particularly relevant in human S100A6 protein and in fish Gad m 1 allergenic protein, which are implicated in human disease processes. Here, we describe detailed methods to generate and monitor the formation of amyloidogenic assemblies and aggregates of these two EF-hand proteins in vitro.
Key wordsCalcium S100A6 Gad m 1 Fish allergens Amyloids EF-hand
- Gad m 1
Allergome nomenclature of Atlantic cod β-parvalbumin with UniProtKB sequence A51783
This work was partly supported by Fundação para a Ciência e a Tecnologia (FCT/MCTES, Portugal) through grants UID/Multi/04046/2013 (to BioISI/C.M.G.), PTDC/NEU-NMC/2138/2014 (to C.M.G.), IF/01046/2014 (to C.M.G.). Bial Foundation is acknowledged through grant PT/FB/BL-2014-343 (to C.M.G.). AEI/EU-FEDER (Spain) is acknowledged for grants SAF2014-52661-C3 and BFU2015-72271-EXP (to M.G.). J.S.C. was a recipient of a Ph.D. fellowship (SFRH/BD/101171/2014) from Fundação para a Ciência e a Tecnologia (FCT/MCTES, Portugal). G. Fritz (Freiburg University) is gratefully acknowledged for the S100A6 expression plasmid.