Electro-optical properties characterization of Fish Type III Antifreeze Protein

SALVAY, ANDRES G.; SANTOS, JAVIER; HOWARD, EDUARDO I

Journal Of Biological Physics

Año: 2007 p. 1 - 1

0092-0606

Antifreeze proteins (AFPs) are ice-binding proteins that depress the freezingpoint of water in a non-colligative manner without a significant modification of the meltingpoint. Found in the blood and tissues of some organisms (such as fish, insects, plants andsoil bacteria) AFPs play an important role in subzero temperature survival. Fish Type IIIAFP are present in members of the subclass Zoarcoidei. AFPIII are small 7 kDa –or 14 kDatandem– globular proteins. In the present work we study the behavior of several physicalproperties such as low-frequency dielectric permittivity spectrum, circular dichroism, andelectrical conductivity of Fish Type III AFP solutions measured at different concentrations.The combination of the information obtained from these measurements could be explainedthrough the formation of AFP molecular aggregates or, alternatively, by the existence ofsome other type of inter-particle interactions. Thermal stability and electro-optical behaviorwhen proteins are dissolved in deuterated water were also investigated.Keywords