Formation of Insulin (C254H377N65O75S6 )
Mol.Wt : 5734Da
Mol.Wt : 5734Da
Preproinsulin ------>Proinsulin ---------------> Insulin
(110 amino acids) (86 amino acids) (51 amino acids)
(110 amino acids) (86 amino acids) (51 amino acids)
NH2-------|-----------|-------------|------|-COOH
(signal peptide-24AA) (B-chain 30 AA) (C-chain 35AA) (A-chain 21AA) [AA-amino acid]
Preproinsulin Primary Structure -Schematic
(signal peptide-24AA) (B-chain 30 AA) (C-chain 35AA) (A-chain 21AA) [AA-amino acid]
Preproinsulin Primary Structure -Schematic
Signal peptide helps preproinsulin to enter secretion pathway but during translation it is cleaved off
leaving behind proinsulin with amino group attached to B-chain at one end and -COOH group attached
to A -chain at the other end with C-chain in between.Hydrophobicity of signal peptide helps in transport
of the nascent chain through microsomal membrane of Rough Endoplasmic Reticulum.
leaving behind proinsulin with amino group attached to B-chain at one end and -COOH group attached
to A -chain at the other end with C-chain in between.Hydrophobicity of signal peptide helps in transport
of the nascent chain through microsomal membrane of Rough Endoplasmic Reticulum.
NH2|-----------|-------------|------|-COOH
(B-chain 30 AA) (C-chain 35AA) (A-chain 21AA)
proinsulin Primary Structure -Schematic
(B-chain 30 AA) (C-chain 35AA) (A-chain 21AA)
proinsulin Primary Structure -Schematic
In proinsulin,the B-chain & A-chain are connected by C-peptide flanked by 2 pairs of basic amino
acids,Arg-Arg at B-end & Lys-Arg at A-end.
acids,Arg-Arg at B-end & Lys-Arg at A-end.
arg-arg-glu-ala-glu-asp-leu-gln-val-gly-gln-val-glu-leu-gly-gly-gly-pro-gly-ala-gly-ser-leu-gln-pro-leu-ala-leu-gln-gly-ser-leu-gln-lys-arg
( Primary structure of C-peptide }
( Primary structure of C-peptide }