1exs
From Proteopedia
(New page: 200px<br /><applet load="1exs" size="450" color="white" frame="true" align="right" spinBox="true" caption="1exs, resolution 2.39Å" /> '''STRUCTURE OF PORCINE...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1exs.gif|left|200px]]<br /><applet load="1exs" size=" | + | [[Image:1exs.gif|left|200px]]<br /><applet load="1exs" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1exs, resolution 2.39Å" /> | caption="1exs, resolution 2.39Å" /> | ||
'''STRUCTURE OF PORCINE BETA-LACTOGLOBULIN'''<br /> | '''STRUCTURE OF PORCINE BETA-LACTOGLOBULIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | beta-Lactoglobulin (BLG) is a lipocalin and is the major protein in the | + | beta-Lactoglobulin (BLG) is a lipocalin and is the major protein in the whey of the milk of cows and other ruminants, but not in all mammalian species. The biological function of BLG is not clear, but a potential role in carrying fatty acids through the digestive tract has been proposed. The capability of BLG to aggregate and form gels is often used to thicken foodstuffs. The structure of the porcine form is sufficiently different from other known BLG structures that SIRAS phases had to be measured in order to solve the crystal structure to 2.4 A resolution. The r.m.s. deviation of C(alpha) atoms is 2.8 A between porcine and bovine BLG. Nevertheless, the typical lipocalin fold is conserved. Compared with bovine BLG, the tilted alpha-helix alters the arrangement of surface residues of the porcine form, completely changing the dimerization behaviour. Through a unique pH-dependent domain-swapping mechanism involving the first ten residues, a novel dimer interface is formed at the N-terminus of porcine BLG. The existence of this novel dimer at low pH is supported by gel-filtration experiments. These results provide a rationale for the difference in physicochemical behaviour between bovine and porcine BLG and point the way towards engineering such dimerization motifs into other members of the lipocalin family. |
==About this Structure== | ==About this Structure== | ||
| - | 1EXS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with NA and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1EXS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with <scene name='pdbligand=NA:'>NA</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EXS OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Sus scrofa]] | [[Category: Sus scrofa]] | ||
| - | [[Category: Abrahams, J | + | [[Category: Abrahams, J P.]] |
| - | [[Category: Hoedemaeker, F | + | [[Category: Hoedemaeker, F J.]] |
[[Category: GOL]] | [[Category: GOL]] | ||
[[Category: NA]] | [[Category: NA]] | ||
[[Category: lipocalin fold]] | [[Category: lipocalin fold]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:32:35 2008'' |
Revision as of 10:32, 21 February 2008
|
STRUCTURE OF PORCINE BETA-LACTOGLOBULIN
Overview
beta-Lactoglobulin (BLG) is a lipocalin and is the major protein in the whey of the milk of cows and other ruminants, but not in all mammalian species. The biological function of BLG is not clear, but a potential role in carrying fatty acids through the digestive tract has been proposed. The capability of BLG to aggregate and form gels is often used to thicken foodstuffs. The structure of the porcine form is sufficiently different from other known BLG structures that SIRAS phases had to be measured in order to solve the crystal structure to 2.4 A resolution. The r.m.s. deviation of C(alpha) atoms is 2.8 A between porcine and bovine BLG. Nevertheless, the typical lipocalin fold is conserved. Compared with bovine BLG, the tilted alpha-helix alters the arrangement of surface residues of the porcine form, completely changing the dimerization behaviour. Through a unique pH-dependent domain-swapping mechanism involving the first ten residues, a novel dimer interface is formed at the N-terminus of porcine BLG. The existence of this novel dimer at low pH is supported by gel-filtration experiments. These results provide a rationale for the difference in physicochemical behaviour between bovine and porcine BLG and point the way towards engineering such dimerization motifs into other members of the lipocalin family.
About this Structure
1EXS is a Single protein structure of sequence from Sus scrofa with and as ligands. Full crystallographic information is available from OCA.
Reference
A novel pH-dependent dimerization motif in beta-lactoglobulin from pig (Sus scrofa)., Hoedemaeker FJ, Visschers RW, Alting AC, de Kruif KG, Kuil ME, Abrahams JP, Acta Crystallogr D Biol Crystallogr. 2002 Mar;58(Pt 3):480-6. Epub 2002, Feb 21. PMID:11856834
Page seeded by OCA on Thu Feb 21 12:32:35 2008
