TRYPTOPHAN-19 OF BETA-LACTOGLOBULIN, THE ONLY RESIDUE COMPLETELY CONSERVED IN THE LIPOCALIN SUPERFAMILY, IS NOT ESSENTIAL FOR BINDING RETINOL, BUT RELEVANT TO STABILIZING BOUND RETINOL AND MAINTAINING ITS STRUCTURE

被引:57
作者
KATAKURA, Y
TOTSUKA, M
AMETANI, A
KAMINOGAWA, S
机构
[1] Department of Agricultural Chemistry, The University of Tokyo, Tokyo, 113
来源
BIOCHIMICA ET BIOPHYSICA ACTA-PROTEIN STRUCTURE AND MOLECULAR ENZYMOLOGY | 1994年 / 1207卷 / 01期
关键词
BETA-LACTOGLOBULIN; SITE-DIRECTED MUTAGENESIS; RETINOL BINDING; CONFORMATIONAL STABILITY; STRUCTURAL PERTURBATION; CONSERVED RESIDUE;
D O I
10.1016/0167-4838(94)90051-5
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Residue 19 of tryptophan in bovine beta-lactoglobulin (beta-LG) is the only invariant residue throughout the lipocalin superfamily having two characteristic features: binding ability for small hydrophobic molecules and the unique beta-barrel three-dimensional structure. In this study, we investigated whether this strictly conserved Trp-19 of beta-LG would be indispensable for its structure and function such as maintaining the molecular structure and biological activity of beta-LG. Spectroscopic and enzymatic oxidation experiments on retinol bound to W19Y, in which Tyr was substituted for Trp-19, showed that Trp-19 was not critical for this binding, but was important for stably maintaining the environment surrounding retinol and the bound retinol. An analysis, using four anti-beta-LG monoclonal antibodies as probes, revealed a structural change in region 20-29, but not in the reverse region of Trp-19. A guanidine hydrochloride-induced unfolding study showed that the conformational stability of W19Y was greatly reduced by 6.9 kcal/mol compared to that of wild-type beta-LG. These facts indicated that Trp-19 is one of the important residues in correctly maintaining the local structure of beta-LG and stably retaining its overall structure, thereby conserving the bound retinol molecule.
引用
收藏
页码:58 / 67
页数:10
相关论文
共 29 条
[1]   CHARACTERIZATION OF THE GENE ENCODING OVINE BETA-LACTOGLOBULIN - SIMILARITY TO THE GENES FOR RETINOL BINDING-PROTEIN AND OTHER SECRETORY PROTEINS [J].
ALI, S ;
CLARK, AJ .
JOURNAL OF MOLECULAR BIOLOGY, 1988, 199 (03) :415-426
[2]  
[Anonymous], INTRO PROTEIN STRUCT
[3]   BINDING AFFINITIES OF RETINOL AND RELATED COMPOUNDS TO RETINOL BINDING-PROTEINS [J].
COGAN, U ;
KOPELMAN, M ;
MOKADY, S ;
SHINITZKY, M .
EUROPEAN JOURNAL OF BIOCHEMISTRY, 1976, 65 (01) :71-78
[4]   CRYSTALLOGRAPHIC REFINEMENT OF HUMAN SERUM RETINOL BINDING-PROTEIN AT 2A RESOLUTION [J].
COWAN, SW ;
NEWCOMER, ME ;
JONES, TA .
PROTEINS-STRUCTURE FUNCTION AND GENETICS, 1990, 8 (01) :44-61
[5]   SPECTROSCOPIC CHARACTERIZATION OF BETA-LACTOGLOBULIN-RETINOL COMPLEX [J].
FUGATE, RD ;
SONG, PS .
BIOCHIMICA ET BIOPHYSICA ACTA, 1980, 625 (01) :28-42
[6]  
FUTTERMAN S, 1972, J BIOL CHEM, V247, P5168
[7]  
GREENE RF, 1974, J BIOL CHEM, V249, P5388
[8]  
HATTORI M, 1993, J BIOL CHEM, V268, P22414
[9]   THE EFFECTS OF CULTURE CONDITIONS ON THE SECRETION OF HUMAN LYSOZYME BY SACCHAROMYCES-CEREVISIAE A2-1-1A [J].
ICHIKAWA, K ;
KOMIYA, K ;
SUZUKI, K ;
NAKAHARA, T ;
JIGAMI, Y .
AGRICULTURAL AND BIOLOGICAL CHEMISTRY, 1989, 53 (10) :2687-2694
[10]  
INAKA K, 1991, J BIOL CHEM, V266, P12599