Thermodynamic and functional properties of legumin (11S globulin from Vicia faba) in the presence of small-molecule surfactants: effect of temperature and pH.
We report on the effect of a set of water-dispersible small-molecule surfactants (the main and the longest-hydrocarbon components of which are a citric acid ester of monostearate, a sodium salt of stearol-lactoyl lactic acid, and a polyglycerol ester of stearic acid) on molecular, thermodynamic, and functional properties of the major storage protein of broad beans (Vicia faba) legumin in different molecular states (native, heated, and acid-denatured). The interaction between legumin and the surfactants has been characterized by a combination of thermodynamic methods, namely, mixing calorimetry and multiangle laser static and dynamic light scattering. It was found that hydrogen bonds, electrostatic interactions, and hydrophobic contacts provided a basis for the interactions between the surfactants and both the native and the denatured protein in aqueous medium. Intensive association of the protein molecules in a bulk aqueous medium in the presence of the surfactants was revealed by static and dynamic laser light scattering. In consequence of this, both the surface activity and the gel-forming ability of legumin increased markedly, which has been shown by tensiometry, estimation of protein foaming capacity, and steady-state viscometry. A likely molecular mechanism underlying the effects of small-molecule surfactants on legumin structure-forming properties at the interface and in a bulk aqueous medium is discussed.
Institute of Biochemical Physics of Russian Academy of Sciences, Vavilov str. 28, Moscow 119991, Russia.
Michael M
MM
Il'in
Maria G
MG
Semenova
Larisa E
LE
Belyakova
Anna S
AS
Antipova
Yurii N
YN
Polikarpov
D000143:Acids / Q000737:chemistry; D002151:Calorimetry; D005990:Glycerol / Q000031:analogs & derivatives / Q000737:chemistry; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D050178:Monoglycerides; D010316:Particle Size; D010940:Plant Proteins / Q000737:chemistry*; D011489:Protein Denaturation; D013228:Stearates / Q000737:chemistry; D013499:Surface Properties; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D031307:Vicia faba / Q000737:chemistry*; D014783:Viscosity; D000097793:Legumins
D000143:Acids; D005990:Glycerol; D050178:Monoglycerides; D010940:Plant Proteins; D013228:Stearates; D013501:Surface-Active Agents; D000097793:Legumins; C480659:polyglycerol monostearate; C031568:stearoyl-2-lactylic acid