Effect of salt and heating on a mesoscopic structure composed of ovalbumin globules in aqueous solution.
Mesoscopic structural changes of an ovalbumin solution by heating and adding NaCl have been investigated with a small-angle neutron scattering method. In the natural solution, a broad peak at q = 0.057 A(-1), which disappeared by adding NaCl, indicates the existence of an electrostatic long-range interaction between the ovalbumin globules. Along with the broad peak, a prominent intensity increase in a very small q region was observed on heating except for the initial and final stages, indicating the coexistence of a disordered structure of the denatured ovalbumin and a regular-interspacing structure of the natural ovalbumin globules. Though the macroscopic feature in the final stage, whether the solution forms a gel (10 wt %) or not (5 wt %), strongly depended on the concentration of the ovalbumin, the scattering profiles showed a common characteristic feature: the appearance of a new peak around q = 0.023 A(-1), which indicates the emergence of another regular structure.
Sugiyama
M
M
Department of Physics, Kyushu University, Fukuoka 812-8581, Japan.
Nakamura
A
A
Hiramatsu
N
N
Annaka
M
M
Kuwajima
S
S
Hara
K
K
D000818:Animals; D002645:Chickens; D005782:Gels / Q000737:chemistry*; D006358:Hot Temperature; D009502:Neutrons; D010047:Ovalbumin / Q000737:chemistry*; D012542:Scattering, Radiation; D012965:Sodium Chloride / Q000494:pharmacology*; D012996:Solutions; D014867:Water
D005782:Gels; D012996:Solutions; D014867:Water; D012965:Sodium Chloride; D010047:Ovalbumin