TY - JOUR
T1 - β-glycosidase from the hyperthermophilic archaeon Sulfolobus solfataricus
T2 - Structure and activity in the presence of alcohols
AU - D'Auria, Sabato
AU - Nucci, Roberto
AU - Rossi, Mose'
AU - Bertoli, Enrico
AU - Tanfani, Fabio
AU - Gryczynski, Ignacy
AU - Malak, Henry
AU - Lakowicz, Joseph R.
PY - 1999
Y1 - 1999
N2 - β-Glycosidase from the extreme thermophilic archaeon Sulfolobus solfataricus is a tetrameric protein with a molecular mass of 240 kDa, stable in the presence of detergents, and with a maximal activity at temperatures above 95°C. Understanding the structure-activity relationships of the enzyme under different conditions is of fundamental importance for both theoretical and applicative purposes. In this paper we report the effect of methanol, ethanol, 1-propanol, and 1-butanol on the activity of S. solfataricus β-glycosidase expressed in Escherichia coli. The alcohols stimulated the enzyme activity, with 1-butanol producing its maximum effect at a lower concentration than the other alcohols. The structure of the enzyme was studied in the presence of 1-butanol by circular dichroism and Fourier-transform infrared and fluorescence spectroscopies. Circular dichroism and steady-state fluorescence measurements revealed that at low temperatures the presence of the alcohol produced no significant changes in the tertiary structure of the enzyme. However, time-resolved fluorescence data showed that the alcohol modifies the protein microenvironment, leading to a more flexible enzyme structure, which is probably responsible for the enhanced enzymatic activity.
AB - β-Glycosidase from the extreme thermophilic archaeon Sulfolobus solfataricus is a tetrameric protein with a molecular mass of 240 kDa, stable in the presence of detergents, and with a maximal activity at temperatures above 95°C. Understanding the structure-activity relationships of the enzyme under different conditions is of fundamental importance for both theoretical and applicative purposes. In this paper we report the effect of methanol, ethanol, 1-propanol, and 1-butanol on the activity of S. solfataricus β-glycosidase expressed in Escherichia coli. The alcohols stimulated the enzyme activity, with 1-butanol producing its maximum effect at a lower concentration than the other alcohols. The structure of the enzyme was studied in the presence of 1-butanol by circular dichroism and Fourier-transform infrared and fluorescence spectroscopies. Circular dichroism and steady-state fluorescence measurements revealed that at low temperatures the presence of the alcohol produced no significant changes in the tertiary structure of the enzyme. However, time-resolved fluorescence data showed that the alcohol modifies the protein microenvironment, leading to a more flexible enzyme structure, which is probably responsible for the enhanced enzymatic activity.
KW - Archaeon
KW - Circular dichroism
KW - Frequency domain fluorometry
KW - Infrared spectroscopy
KW - Organic solvent
KW - β-glycosidase
UR - http://www.scopus.com/inward/record.url?scp=0032879588&partnerID=8YFLogxK
U2 - 10.1093/oxfordjournals.jbchem.a022484
DO - 10.1093/oxfordjournals.jbchem.a022484
M3 - Article
C2 - 10467170
AN - SCOPUS:0032879588
SN - 0021-924X
VL - 126
SP - 545
EP - 552
JO - Journal of Biochemistry
JF - Journal of Biochemistry
IS - 3
ER -