The effects of sucrose and fructose on the free energy of unfolding, DeltaG(N-->D), and on the change in hydrodynamic radius, R(H), upon unfolding were measured for RNase A and alpha-lactalbumin. Recently we analyzed the results for RNase A and showed that the effects of the carbohydrates on the protein's thermal stability can be accurately accounted for by scaled particle theory (SPT), and are thus largely entropic in nature. In this paper we extend this analysis to alpha-lactalbumin and demonstrate the generality of this finding. We also investigate the relationship between SPT and the thermodynamic formalism of preferential interactions. The preferential binding parameters calculated using SPT are in excellent agreement with experimentally measured values available in the literature. This agreement is expected to hold as long as enthalpic interactions between the cosolute and the protein are not important, as appears to be the case here. Finally we use the experimental data and SPT to calculate the change in the number of sugar molecules excluded from the protein surface during unfolding from knowledge of the preferential binding parameter for the native and denatured state of the protein. Study holds ProTherm entries: 22462, 22463, 22464, 22465, 22466, 22467, 22468, 22469, 22470, 22471, 22472, 22473, 22474, 22475, 22476, 22477, 22478, 22479, 22480, 22481, 22482, 22483, 22484, 22485, 22486, 22487, 22488, 22489, 22490, 22491, 22492, 22493, 22494, 22495, 22496, 22497, 22498, 22499, 22500, 22501, 22502, 22503 Extra Details: Protein stability; Carbohydrate; Scaled particle theory; Preferential interactions; Capillary electrophoresis
ID: ccNHnuTV4
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:53 p.m.
Version: 1
Colors: | D | E | R | H | K | S | T | N | Q | A | V | I | L | M | F | Y | W | C | G | P |
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Percent Identity | Matching Chains | Protein | Accession | Entry Name |
---|---|---|---|---|
100.0 | Ribonuclease pancreatic | P61824 | RNAS1_BISBI | |
100.0 | Ribonuclease pancreatic | P61823 | RNAS1_BOVIN | |
96.8 | Ribonuclease pancreatic | P67926 | RNAS1_CAPHI | |
96.8 | Ribonuclease pancreatic | P67927 | RNAS1_SHEEP | |
95.2 | Ribonuclease pancreatic | P00657 | RNAS1_BUBBU | |
96.0 | Ribonuclease pancreatic | P07847 | RNAS1_AEPME | |
93.5 | Ribonuclease pancreatic | P07848 | RNAS1_EUDTH | |
95.2 | Ribonuclease pancreatic | P00660 | RNAS1_CONTA | |
92.7 | Ribonuclease pancreatic | P00668 | RNAS1_ANTAM | |
90.3 | Ribonuclease pancreatic | P00662 | RNAS1_GIRCA | |
96.0 | Ribonuclease pancreatic | Q29606 | RNAS1_ORYLE | |
100.0 | Alpha-lactalbumin | P00711 | LALBA_BOVIN | |
99.3 | Alpha-lactalbumin | Q9TSR4 | LALBA_BOSMU | |
98.6 | Alpha-lactalbumin | Q9TSN6 | LALBA_BUBBU | |
97.2 | Alpha-lactalbumin | P09462 | LALBA_SHEEP | |
95.1 | Alpha-lactalbumin | P00712 | LALBA_CAPHI |