Investigation of apomyoglobin stability depending on urea and temperature at two different pH values
Baryshnikova, E.N.; Sharanov, M.G.; Kashparov, I.A.; Il'ina, N.B.; Bychkova, V.E.
Molekuliarnaia Biologiia 39(2): 330-335
2005
ISSN/ISBN: 0026-8984 PMID: 15856957 Document Number: 593080
Equilibrium unfolding of apomyoglobin by urea was investigated in the temperature range from 5 to 25 degrees C at two pH values. The thermodynamic parameters of the apomyoglobin native-unfolded state transition were determined. Conformational changes in the protein structure were monitored by tryptophan fluorescence and far UV circular dichroism. Apomyoglobin preserves its native conformation at pH 5.7 and 6.2 in the temperature range used. It was shown that the apomyoglobin stability and its unfolding cooperativity are substantially lower at 5 degrees C than at other temperatures. This fact should be taken in account at the investigation of apomyoglobin.