TY - JOUR
T1 - Structure, aggregation dynamics and crystallization of superfolder green fluorescence protein
T2 - Effect of long alkyl chain imidazolium ionic liquids
AU - Han, Qi
AU - Darmanin, Connie
AU - Rosado, Carlos J.
AU - Veríssimo, Nathalia Vieira
AU - Pereira, Jorge F.B.
AU - Bryant, Gary
AU - Drummond, Calum J.
AU - Greaves, Tamar L.
N1 - Funding Information:
The authors acknowledge funding support from the Australian Research Council under its Discovery grant Scheme for this work ( DP230101712 ). The authors also acknowledge the use of the SAXS/WAXS beamline at the Australian Synchrotron, Melbourne, Australia and the RMIT Microscopy and Microanalysis Facility (RMMF) at RMIT University. Jorge F. B. Pereira acknowledges the funding for CIEPQPF, which is supported by the Fundação para a Ciência e a Tecnologia (FCT) through the projects UIDB/EQU/00102/2020 and UIDP/EQU/00102/2020 . We also thank Mr. Xingyu Guo, RMIT University, Australia, for the generous help of crystallization experiments.
Funding Information:
The authors acknowledge funding support from the Australian Research Council under its Discovery grant Scheme for this work (DP230101712). The authors also acknowledge the use of the SAXS/WAXS beamline at the Australian Synchrotron, Melbourne, Australia and the RMIT Microscopy and Microanalysis Facility (RMMF) at RMIT University. Jorge F. B. Pereira acknowledges the funding for CIEPQPF, which is supported by the Fundação para a Ciência e a Tecnologia (FCT) through the projects UIDB/EQU/00102/2020 and UIDP/EQU/00102/2020. We also thank Mr. Xingyu Guo, RMIT University, Australia, for the generous help of crystallization experiments.
Publisher Copyright:
© 2023
PY - 2023/12/31
Y1 - 2023/12/31
N2 - Green fluorescent protein (GFP) and its variants are widely used in medical and biological research, especially acting as indicators of protein structural integrity, protein-protein interactions and as biosensors. This study employs superfolder GFP (sfGFP) to investigate the impact of varying alkyl chain length of 1-Cn-3-methylimidazolium chloride ionic liquid (IL) series ([Cnmim]Cl, n = 2, 4, 6, 8, 10, 12) on the protein fluorescence, structure, hydration, aggregation dynamics and crystallization behaviour. The results revealed a concentration-dependent decrease in the sfGFP chromophore, particularly in long alkyl chain ILs ([C10mim]Cl and [C12mim]Cl). Tryptophan (Trp) fluorescence showed the quenching rate increased with longer alkyl chains indicating a nonpolar interaction between Trp57 and the alkyl chain. Secondary structural changes were observed at the high IL concentration of 1.5 M in [C10mim]Cl and [C12mim]Cl. Small-angle X-ray scattering (SAXS) indicated relatively stable protein sizes, but with IL aggregates present in [C10mim]Cl and [C12mim]Cl solutions. Dynamic light scattering (DLS) data showed increased protein size and aggregation with longer alkyl chain ILs. Notably, ILs and salts, excluding [C2mim]Cl, promoted sfGFP crystallization. This study emphasizes the influence of the cation alkyl chain length and concentration on protein stability and aggregation, providing insights into utilizing IL solvents for protein stabilization and crystallization purposes.
AB - Green fluorescent protein (GFP) and its variants are widely used in medical and biological research, especially acting as indicators of protein structural integrity, protein-protein interactions and as biosensors. This study employs superfolder GFP (sfGFP) to investigate the impact of varying alkyl chain length of 1-Cn-3-methylimidazolium chloride ionic liquid (IL) series ([Cnmim]Cl, n = 2, 4, 6, 8, 10, 12) on the protein fluorescence, structure, hydration, aggregation dynamics and crystallization behaviour. The results revealed a concentration-dependent decrease in the sfGFP chromophore, particularly in long alkyl chain ILs ([C10mim]Cl and [C12mim]Cl). Tryptophan (Trp) fluorescence showed the quenching rate increased with longer alkyl chains indicating a nonpolar interaction between Trp57 and the alkyl chain. Secondary structural changes were observed at the high IL concentration of 1.5 M in [C10mim]Cl and [C12mim]Cl. Small-angle X-ray scattering (SAXS) indicated relatively stable protein sizes, but with IL aggregates present in [C10mim]Cl and [C12mim]Cl solutions. Dynamic light scattering (DLS) data showed increased protein size and aggregation with longer alkyl chain ILs. Notably, ILs and salts, excluding [C2mim]Cl, promoted sfGFP crystallization. This study emphasizes the influence of the cation alkyl chain length and concentration on protein stability and aggregation, providing insights into utilizing IL solvents for protein stabilization and crystallization purposes.
KW - Dynamic light scattering
KW - Green fluorescent protein
KW - Imidazolium chloride
KW - Ionic liquids
KW - Protein crystallization
KW - Small-angle X-ray scattering (SAXS)
UR - https://www.scopus.com/pages/publications/85174435394
U2 - 10.1016/j.ijbiomac.2023.127456
DO - 10.1016/j.ijbiomac.2023.127456
M3 - Article
C2 - 37844813
AN - SCOPUS:85174435394
SN - 0141-8130
VL - 253
JO - International Journal of Biological Macromolecules
JF - International Journal of Biological Macromolecules
M1 - 127456
ER -