Molecular dynamics of microbial lipases as determined from their intrinsic tryptophan fluorescence

被引:30
作者
Graupner, M
Haalck, L
Spener, F
Lindner, H
Glatter, O
Paltauf, F
Hermetter, A [1 ]
机构
[1] Graz Tech Univ, Dept Biochem, A-8010 Graz, Austria
[2] Univ Munster, Dept Biochem, D-48149 Munster, Germany
[3] Graz Univ, Dept Phys Chem, A-8010 Graz, Austria
基金
奥地利科学基金会;
关键词
D O I
10.1016/S0006-3495(99)76906-7
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
We have studied the intrinsic tryptophan fluorescence of the lipases from Chromobacterium viscosum (CVL), Pseudomonas species (PSL), and Rhizopus oryzae (ROL) in aqueous buffer, zwitterionic detergent micelles, and isopropanol-water mixtures. It was the purpose of this study to obtain information about biophysical properties of the respective enzymes under conditions that modulate enzyme activities and stereoselectivities to a significant extent. According to their decay-associated emission spectra, CVL tryptophans are located in the hydrophobic interior of the protein. in contrast, the PSL and ROL tryptophans are probably confined to the core and the surface of the lipase. From the tryptophan lifetime distributions it can be concluded that the conformation of CVL is not much affected by detergent or organic solvent (isopropanol). Accordingly, CVL is enzymatically active in these systems and most active in the presence of isopropanol. In contrast, ROL and PSL show high conformational mobility, depending on the solvent, because their lifetime distributions are very different in the presence and absence of detergent or isopropanol. Time-resolved anisotropy studies provided evidence that the lipases exhibit very high internal molecular flexibility. This peculiar feature of lipases is perhaps the key to the great differences in activity and stereoselectivity observed in different reaction media. Furthermore, information about self-association of the lipases in different solvents could be obtained. PSL, but not CVL and ROL, forms aggregates in water. Lipase aggregation can be reversed by the addition of detergent or isopropanol, which competes for the hydrophobic surface domains of this protein. This dissociation could efficiently contribute to the increase in lipase activity in the presence of a detergent or isopropanol.
引用
收藏
页码:493 / 504
页数:12
相关论文
共 27 条
[1]   INTERPRETATION OF FLUORESCENCE DECAYS IN PROTEINS USING CONTINUOUS LIFETIME DISTRIBUTIONS [J].
ALCALA, JR ;
GRATTON, E ;
PRENDERGAST, FG .
BIOPHYSICAL JOURNAL, 1987, 51 (06) :925-936
[2]   FLUORESCENCE LIFETIME DISTRIBUTIONS IN PROTEINS [J].
ALCALA, JR ;
GRATTON, E ;
PRENDERGAST, FG .
BIOPHYSICAL JOURNAL, 1987, 51 (04) :597-604
[3]   MULTIPLE CONFORMATIONAL STATES IN MYOGLOBIN REVEALED BY FREQUENCY-DOMAIN FLUOROMETRY [J].
BISMUTO, E ;
IRACE, G ;
GRATTON, E .
BIOCHEMISTRY, 1989, 28 (04) :1508-1512
[4]   A MODEL FOR INTERFACIAL ACTIVATION IN LIPASES FROM THE STRUCTURE OF A FUNGAL LIPASE-INHIBITOR COMPLEX [J].
BRZOZOWSKI, AM ;
DEREWENDA, U ;
DEREWENDA, ZS ;
DODSON, GG ;
LAWSON, DM ;
TURKENBURG, JP ;
BJORKLING, F ;
HUGEJENSEN, B ;
PATKAR, SA ;
THIM, L .
NATURE, 1991, 351 (6326) :491-494
[5]  
Chu B., 1991, LASER LIGHT SCATTERI, V2nd
[6]  
DEMCHENKO AP, 1992, TOPICS FLUORESCENCE, V3, P81
[7]  
Duque M, 1996, J LIPID RES, V37, P868
[8]  
FABER K, 1992, BIOTRANSFORMATIONS O
[9]  
HAALCK L, 1994, THESIS WESTFALISCHE
[10]  
Lakowicz J. R., 2010, PRINCIPLES FLUORESCE