Bioelectret state induced by water in lipases

Author

Bridelli, M.G. ; Capelletti, R. ; Maraia, F. ; Mora, C. ; Pirola, L.

Author_Institution

Dipt. di Fisica, Parma Univ., Italy

fYear

1999

fDate

1999

Firstpage

213

Lastpage

216

Abstract

Lipase from Candida lipolytica (as pellets and/or films) is studied by means of TSDC (Thermally Stimulated Depolarization Currents) technique with the aim to investigate the role played by water in this biopolymer endowed with a large external hydrophobic surface. Two main broad TSDC bands (a weak one at T-150 K and a stronger one at T-260 K) are detected. The peaks amplitudes and positions critically depend not only on the water content in the protein but also on the hydration history of the sample. Complementary isotherms of absorption and desorption of water in and on the protein, performed by means of gravimetric method, allow to reveal a marked hysteresis in the interaction of lipase with the aqueous solvent,

Keywords

bioelectric phenomena; dielectric hysteresis; electrets; proteins; solvation; thermally stimulated currents; Candida lipolytica; Thermally Stimulated Depolarization Currents; absorption; bioelectret state; desorption; hydration history; large external hydrophobic surface; lipases; protein; water; Absorption; Annealing; Biochemistry; History; Humidity; Physics; Polarization; Proteins; Solvents; Temperature distribution;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrets, 1999. ISE 10. Proceedings. 10th International Symposium on

Conference_Location

Athens

Print_ISBN

0-7803-5025-1

Type

conf

DOI

10.1109/ISE.1999.831981

Filename

831981