Water induced TSDC in hemoglobin and myoglobin

Author

Bridelli, Maria Grazia ; Capelletti, R. ; Losi, Stefania ; Mozzarelli, A. ; Vecli, Arnaldo

Author_Institution

Dipartimento di Fisica, Parma Univ., Italy

fYear

1994

fDate

7-9 Sep 1994

Firstpage

869

Lastpage

874

Abstract

The hydration of hemoglobin (Hb) and myoglobin (Mb) has been investigated by the Thermally Stimulated Depolarization Currents (TSDC) technique. The TSDC spectra as a function of the hydration degree (δ=0.01+0.3 grams of water/grams of protein) and of the annealing time in vacuum were recorded in the temperature range 100-300 K on pellet samples. The distribution of water dipoles for both heme-proteins shows four main peaks in the range 170-300 K, indicating the presence of at least four different classes of bound water. A fifth peak at very low temperatures (T_m~150 K) appears only at low hydration levels and probably it is not related to water dipole relaxations. Possible environments of water dipoles responsible for the TSDC peaks are discussed

Keywords

bioelectric phenomena; dielectric depolarisation; molecular biophysics; proteins; solvation; thermally stimulated currents; 100 to 300 K; 150 K; Thermally Stimulated Depolarization Currents; annealing time; hemoglobin; hydration; hydration levels; myoglobin; water dipole relaxations; Absorption; Annealing; Humans; Iron; Oxidation; Physics; Polarization; Proteins; Temperature distribution; Whales;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrets, 1994. (ISE 8), 8th International Symposium on

Conference_Location

Paris

Print_ISBN

0-7803-1940-0

Type

conf

DOI

10.1109/ISE.1994.515240

Filename

515240