Sandbox-insulin-shelly: Difference between revisions

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Student, Shelly Livne

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 <StructureSection load='' size='500' side='right' scene='User:Whitney_Stoppel/sandbox1/Human_insulin2/1' caption='Human insulin chain A (grey) and chain B (green), [[3i40]]'>
 [[Image:InsulinHexamer.jpg|200px|left]]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
 '''Insulin''' is a hormone that controls [[Carbohydrate Metabolism|carbohydrate metabolism]] and storage in the human body.  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.  Synthesis of human insulin in E. coli is important to producing insulin for the treatment of type 1 diabetes.  Proinsulin (Pins) is processed by several proteases in the Golgi apparatus to form insulin which is shorter by 35 amino acids.  DPI is a monomeric despentapeptide (B26-B30) Ins analogue.  DTRI is a monomeric destripeptide (B28-B30) Ins analogue.  DHPI is for desheptapeptide (B24-B30) Ins.  LIns is a legume Ins.
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Insulin is made up of two pieces called the A- and B-chain, shown above in blue and green respectively.  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 is composed of two different types of peptide chains. <scene name='34/347648/Chain_a/1'>Chain A</scene> has 21 amino acids and <scene name='34/347648/Chain_b/1'>Chain B</scene> has 30 amino acids.  Both chains contain <scene name='34/347648/Secondary_structures/1'>alpha helices</scene> but no beta strands. There are 3 conserved <scene name='34/347648/Disulfide_bonds/1'>disulfide bridges</scene> which help keep the two chains together.  Insulin can also form <scene name='User:Whitney_Stoppel/sandbox1/Insulin_dimer/2'>dimers</scene> in solution due to the hydrogen bonding between the B chains (shown as white lines).  The dimers can further interact to form <scene name='User:Whitney_Stoppel/sandbox1/Insulin_hexamer/4'>hexamers</scene> due to interaction between hydrophobic surfaces.  This <scene name='User:Whitney_Stoppel/sandbox1/Insulin_ph7/2'>scene highlights</scene> the hydrophobic (gray) and polar (purple) parts of an insulin monomer at a pH of 7.
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Insulin is able to pair-up with itself and form a dimer by forming hydrogen bonds between the ends of two B-chains.  These <scene name='User:Whitney_Stoppel/sandbox1/Insulin_dimer/2'>hydrogen bonds</scene> are shown above in white.  Then, 3 dimers can come together in the presence of zinc ions and form a hexamer.  Insulin is stored in the <scene name='User:Whitney_Stoppel/sandbox1/Insulin_hexamer/4'>hexameric form</scene> in the body. This <scene name='User:Whitney_Stoppel/sandbox1/Insulin_ph7/2'>scene highlights</scene> the hydrophobic (gray) and polar (purple) parts of an insulin monomer at a pH of 7.  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_Drugs#Treatments|pharmaceutical use]].
 </StructureSection>  For additional details see [[Insulin Structure & Function]].