User:Karsten Theis/Insulin
From Proteopedia
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===Structure of mature insulin=== | ===Structure of mature insulin=== | ||
| - | + | <scene name='82/821037/Spacfilling/1'>Mature insulin</scene> contains two chains, A and B, held together by disulfide bonds and non-covalent interactions. The surface of insulin contains quite a few hydrophobic side chains, which form protein:protein contacts when insulin forms hexamers or binds to its receptor. | |
| + | |||
| + | <jmol> | ||
| + | <jmolRadioGroup> | ||
| + | <item> | ||
| + | <script>background white; select sidechain; color magenta; select sidechain and (cys, met, ile, leu, val, phe, tyr, trp); color gray; set echo ID bla 80% 0%; echo "hydrophobic"; color echo gray; frank off; set echo ID bla2 0% 0%; echo "hydrophilic"; color echo magenta </script> | ||
| + | <text>colored by hydrophobiticity</text> | ||
| + | <checked>true</checked> | ||
| + | </item> | ||
| + | <item> | ||
| + | <script>select sidechain; color white; select sidechain and (asp, glu); color red; select sidechain and (lys, arg, his); color blue; set echo ID bla 80% 0%; echo "positive"; color echo blue; frank off; set echo ID bla2 0% 0%; echo "negative"; color echo red</script> | ||
| + | <text>colored by charge</text> | ||
| + | <checked>false</checked> | ||
| + | </item> | ||
| + | <item> | ||
| + | <script> select sidechain; define ~consurf_to_do selected; define ~consurf_to_color selected; useFullScript = true; consurf_initial_scene = false; script "/wiki/ConSurf/in/4ins_consurf.spt"; set echo ID bla 80% 0%; echo "conserved"; color echo firebrick; frank off; set echo ID bla2 0% 0%; echo "variable"; color echo darkturquoise</script> | ||
| + | <text>colored by conservation</text> | ||
| + | <checked>false</checked> | ||
| + | </item> | ||
| + | </jmolRadioGroup> | ||
| + | </jmol> | ||
| + | |||
| + | |||
| + | These two chains are joined by disulfide bonds, which are shown in yellow. This single piece made up of the A- and B-chains is the active form of the insulin hormone. This is the form that binds the insulin receptor on fat or muscle cells in the body, singling them to take up glucose, or sugar, from the blood and save it for later. Insulin occurs in two states, <scene name='82/821037/Rvst/1'>T or R</scene>. (A) <scene name='82/821037/T6/1'>T6 hexamer</scene>, (B) T3Rf3 hexamer and (C) R6 hexamer. Coordinates were obtained from PDB entries 4INS, 1TRZ and 1ZNJ | ||
===Targeting, processing, and storage=== | ===Targeting, processing, and storage=== | ||
Revision as of 15:39, 10 July 2019
Insulin is a peptide hormone that controls carbohydrate metabolism and storage in the human body[1][2]. It is secreted by specialized cells in the pancreas, enters the bloodstream and reaches other cells. There, it binds to the extracellular side of the insulin receptor, triggering tyrosine kinase activity within the target cell, which in turn regulates glucose uptake, metabolism and storage.
Contents |
Function
The body is able to sense the concentration of glucose in the blood and respond by secreting insulin, which is produced by beta cells in the pancreas.
Disease
Synthesis of human insulin in E. coli is important to producing insulin for the treatment of type 1 diabetes. It is believed that the hydrophobic sections on the B-chain cause insulin aggregation which initially caused problems in the manufacture and storage of insulin for pharmaceutical use.
Structure
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References
- ↑ Sonksen P, Sonksen J. Insulin: understanding its action in health and disease. Br J Anaesth. 2000 Jul;85(1):69-79. PMID:10927996
- ↑ Weiss MA, Lawrence MC. A thing of beauty: Structure and function of insulin's "aromatic triplet". Diabetes Obes Metab. 2018 Sep;20 Suppl 2:51-63. doi: 10.1111/dom.13402. PMID:30230175 doi:http://dx.doi.org/10.1111/dom.13402
- ↑ Davidson HW. (Pro)Insulin processing: a historical perspective. Cell Biochem Biophys. 2004;40(3 Suppl):143-58. PMID:15289650
