1iog
From Proteopedia
(New page: 200px<br /> <applet load="1iog" size="450" color="white" frame="true" align="right" spinBox="true" caption="1iog" /> '''INSULIN MUTANT A3 GLY,(B1, B10, B16, B27)GL...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1iog.gif|left|200px]]<br /> | + | [[Image:1iog.gif|left|200px]]<br /><applet load="1iog" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1iog" size=" | + | |
caption="1iog" /> | caption="1iog" /> | ||
'''INSULIN MUTANT A3 GLY,(B1, B10, B16, B27)GLU, DES-B30, NMR, 19 STRUCTURES'''<br /> | '''INSULIN MUTANT A3 GLY,(B1, B10, B16, B27)GLU, DES-B30, NMR, 19 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Studies of naturally occuring and chemically modified insulins have | + | Studies of naturally occuring and chemically modified insulins have established that the NH2-terminal helix of the A-chain is important in conferring affinity in insulin-receptor interactions. Nevertheless, the three-dimensional structural basis for these observations has not previously been studied in detail. To correlate structure and function in this region of the molecule, we have used the solution structure of an engineered monomer (GluB1, GluB10, GluB16, GluB27, desB30)-insulin (4E insulin) as a template for design of A-chain mutants associated with enhanced or greatly diminished affinity for the insulin receptor. In the context of 4E insulin, the employed mutants, i.e. ThrA8-->His and ValA3-->Gly, result in species with 143% and 0.1% biological activity, respectively, relative to human insulin. The high-resolution NMR studies reveal two well-defined structures each resembling the template. However, significant structural differences are evident notably in residues A2-A8 and their immediate environment. In comparison with the template structure, the A8His mutation enhances the helical character of residues A2-A8. This structural change leads to additional exposure of a hydrophobic patch mainly consisting of species invariant residues. In contrast, the A3Gly mutation leads to stretching and disruption of the A2-A8 helix and changes both the dimensions and the access to the hydrophobic patch exposed in the more active insulins. We conclude that the mutations induce small, yet decisive structural changes that either mediate or inhibit the subtle conformational adjustments involved in the presentation of this part of the insulin pharmacophore to the receptor. |
==Disease== | ==Disease== | ||
| Line 11: | Line 10: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1IOG is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | + | 1IOG is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IOG OCA]. |
==Reference== | ==Reference== | ||
| Line 17: | Line 16: | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Kaarsholm, N | + | [[Category: Kaarsholm, N C.]] |
[[Category: Ludvigsen, S.]] | [[Category: Ludvigsen, S.]] | ||
| - | [[Category: Olsen, H | + | [[Category: Olsen, H B.]] |
[[Category: hormone]] | [[Category: hormone]] | ||
[[Category: human insulin mutant]] | [[Category: human insulin mutant]] | ||
| Line 25: | Line 24: | ||
[[Category: neutral ph]] | [[Category: neutral ph]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:13:55 2008'' |
Revision as of 11:13, 21 February 2008
|
INSULIN MUTANT A3 GLY,(B1, B10, B16, B27)GLU, DES-B30, NMR, 19 STRUCTURES
Contents |
Overview
Studies of naturally occuring and chemically modified insulins have established that the NH2-terminal helix of the A-chain is important in conferring affinity in insulin-receptor interactions. Nevertheless, the three-dimensional structural basis for these observations has not previously been studied in detail. To correlate structure and function in this region of the molecule, we have used the solution structure of an engineered monomer (GluB1, GluB10, GluB16, GluB27, desB30)-insulin (4E insulin) as a template for design of A-chain mutants associated with enhanced or greatly diminished affinity for the insulin receptor. In the context of 4E insulin, the employed mutants, i.e. ThrA8-->His and ValA3-->Gly, result in species with 143% and 0.1% biological activity, respectively, relative to human insulin. The high-resolution NMR studies reveal two well-defined structures each resembling the template. However, significant structural differences are evident notably in residues A2-A8 and their immediate environment. In comparison with the template structure, the A8His mutation enhances the helical character of residues A2-A8. This structural change leads to additional exposure of a hydrophobic patch mainly consisting of species invariant residues. In contrast, the A3Gly mutation leads to stretching and disruption of the A2-A8 helix and changes both the dimensions and the access to the hydrophobic patch exposed in the more active insulins. We conclude that the mutations induce small, yet decisive structural changes that either mediate or inhibit the subtle conformational adjustments involved in the presentation of this part of the insulin pharmacophore to the receptor.
Disease
Known diseases associated with this structure: Diabetes mellitus, rare form OMIM:[176730], Hyperproinsulinemia, familial OMIM:[176730], MODY, one form OMIM:[176730]
About this Structure
1IOG is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The relationship between insulin bioactivity and structure in the NH2-terminal A-chain helix., Olsen HB, Ludvigsen S, Kaarsholm NC, J Mol Biol. 1998 Nov 27;284(2):477-88. PMID:9813131
Page seeded by OCA on Thu Feb 21 13:13:55 2008
