Abstract
Residue 19 of tryptophan in bovine β-lactoglobulin (β-LG) is the only invariant residue throughout the lipocalin superfamily having two characteristic features: binding ability for small hydrophobic molecules and the unique β-barrel three-dimensional structure. In this study, we investigated whether this strictly conserved Trp-19 of β-LG would be indispensable for its structure and function such as maintaining the molecular structure and biological activity of β-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-β-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 β-LG. These facts indicated that Trp-19 is one of the important residues in correctly maintaining the local structure of β-LG and stably retaining its overall structure, thereby conserving the bound retinol molecule.
| Original language | English |
|---|---|
| Pages (from-to) | 58-67 |
| Number of pages | 10 |
| Journal | Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular |
| Volume | 1207 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jul 20 1994 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Biochemistry
- Biophysics
- Molecular Biology
- Structural Biology
Cite this
Tryptophan-19 of β-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. / Katakura, Yoshinori; Totsuka, Mamoru; Ametani, Akio; Kaminogawa, Shuichi.
In: Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular, Vol. 1207, No. 1, 20.07.1994, p. 58-67.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Tryptophan-19 of β-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
AU - Katakura, Yoshinori
AU - Totsuka, Mamoru
AU - Ametani, Akio
AU - Kaminogawa, Shuichi
PY - 1994/7/20
Y1 - 1994/7/20
N2 - Residue 19 of tryptophan in bovine β-lactoglobulin (β-LG) is the only invariant residue throughout the lipocalin superfamily having two characteristic features: binding ability for small hydrophobic molecules and the unique β-barrel three-dimensional structure. In this study, we investigated whether this strictly conserved Trp-19 of β-LG would be indispensable for its structure and function such as maintaining the molecular structure and biological activity of β-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-β-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 β-LG. These facts indicated that Trp-19 is one of the important residues in correctly maintaining the local structure of β-LG and stably retaining its overall structure, thereby conserving the bound retinol molecule.
AB - Residue 19 of tryptophan in bovine β-lactoglobulin (β-LG) is the only invariant residue throughout the lipocalin superfamily having two characteristic features: binding ability for small hydrophobic molecules and the unique β-barrel three-dimensional structure. In this study, we investigated whether this strictly conserved Trp-19 of β-LG would be indispensable for its structure and function such as maintaining the molecular structure and biological activity of β-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-β-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 β-LG. These facts indicated that Trp-19 is one of the important residues in correctly maintaining the local structure of β-LG and stably retaining its overall structure, thereby conserving the bound retinol molecule.
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U2 - 10.1016/0167-4838(94)90051-5
DO - 10.1016/0167-4838(94)90051-5
M3 - Article
VL - 1207
SP - 58
EP - 67
JO - Biochimica et Biophysica Acta - Proteins and Proteomics
JF - Biochimica et Biophysica Acta - Proteins and Proteomics
SN - 1570-9639
IS - 1
ER -