1a78
From Proteopedia
(New page: 200px<br /><applet load="1a78" size="450" color="white" frame="true" align="right" spinBox="true" caption="1a78, resolution 2.0Å" /> '''COMPLEX OF TOAD OVARY...) |
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| - | [[Image:1a78.jpg|left|200px]]<br /><applet load="1a78" size=" | + | [[Image:1a78.jpg|left|200px]]<br /><applet load="1a78" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1a78, resolution 2.0Å" /> | caption="1a78, resolution 2.0Å" /> | ||
'''COMPLEX OF TOAD OVARY GALECTIN WITH THIO-DIGALACTOSE'''<br /> | '''COMPLEX OF TOAD OVARY GALECTIN WITH THIO-DIGALACTOSE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Galectin-1, S-type beta-galactosyl-binding lectins present in vertebrate | + | Galectin-1, S-type beta-galactosyl-binding lectins present in vertebrate and invertebrate species, are dimeric proteins that participate in cellular adhesion, activation, growth regulation, and apoptosis. Two high-resolution crystal structures of B. arenarum galectin-1 in complex with two related carbohydrates, LacNAc and TDG, show that the topologically equivalent hydroxyl groups in the two disaccharides exhibit identical patterns of interaction with the protein. Groups that are not equivalent between the two sugars present in the second moiety of the disaccharide, interact differently with the protein, but use the same number and quality of interactions. The structures show additional protein-carbohydrate interactions not present in previously reported lectin-lactose complexes. These contacts provide an explanation for the enhanced affinity of galectin-1 for TDG and LacNAc relative to lactose. Galectins are in dimer-monomer equilibrium at physiological protein concentrations, suggesting that this equilibrium may be involved in organ-specific regulation of activity. Comparison of B. arenarum with other galectin-1 structures shows that among different galectins there are significant changes in accessible surface area buried upon dimer formation, providing a rationale for the variations observed in the free-energies of dimerization. The structure of the B. arenarum galectin-1 has a large cleft with a strong negative potential that connects the two binding sites at the surface of the protein. Such a striking characteristic suggests that this cleft is probably involved in interactions of the galectin with other intra or extra-cellular proteins. Proteins 2000;40:378-388. |
==About this Structure== | ==About this Structure== | ||
| - | 1A78 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bufo_arenarum Bufo arenarum] with TDG and DTT as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1A78 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bufo_arenarum Bufo arenarum] with <scene name='pdbligand=TDG:'>TDG</scene> and <scene name='pdbligand=DTT:'>DTT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1A78 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Ahmed, H.]] | [[Category: Ahmed, H.]] | ||
| - | [[Category: Amzel, L | + | [[Category: Amzel, L M.]] |
| - | [[Category: Bianchet, M | + | [[Category: Bianchet, M A.]] |
| - | [[Category: Vasta, G | + | [[Category: Vasta, G R.]] |
[[Category: DTT]] | [[Category: DTT]] | ||
[[Category: TDG]] | [[Category: TDG]] | ||
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[[Category: s-lectin]] | [[Category: s-lectin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:41:38 2008'' |
Revision as of 09:41, 21 February 2008
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COMPLEX OF TOAD OVARY GALECTIN WITH THIO-DIGALACTOSE
Overview
Galectin-1, S-type beta-galactosyl-binding lectins present in vertebrate and invertebrate species, are dimeric proteins that participate in cellular adhesion, activation, growth regulation, and apoptosis. Two high-resolution crystal structures of B. arenarum galectin-1 in complex with two related carbohydrates, LacNAc and TDG, show that the topologically equivalent hydroxyl groups in the two disaccharides exhibit identical patterns of interaction with the protein. Groups that are not equivalent between the two sugars present in the second moiety of the disaccharide, interact differently with the protein, but use the same number and quality of interactions. The structures show additional protein-carbohydrate interactions not present in previously reported lectin-lactose complexes. These contacts provide an explanation for the enhanced affinity of galectin-1 for TDG and LacNAc relative to lactose. Galectins are in dimer-monomer equilibrium at physiological protein concentrations, suggesting that this equilibrium may be involved in organ-specific regulation of activity. Comparison of B. arenarum with other galectin-1 structures shows that among different galectins there are significant changes in accessible surface area buried upon dimer formation, providing a rationale for the variations observed in the free-energies of dimerization. The structure of the B. arenarum galectin-1 has a large cleft with a strong negative potential that connects the two binding sites at the surface of the protein. Such a striking characteristic suggests that this cleft is probably involved in interactions of the galectin with other intra or extra-cellular proteins. Proteins 2000;40:378-388.
About this Structure
1A78 is a Single protein structure of sequence from Bufo arenarum with and as ligands. Full crystallographic information is available from OCA.
Reference
Soluble beta-galactosyl-binding lectin (galectin) from toad ovary: crystallographic studies of two protein-sugar complexes., Bianchet MA, Ahmed H, Vasta GR, Amzel LM, Proteins. 2000 Aug 15;40(3):378-88. PMID:10861929
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