Reversed-phase high-performance liquid chromatographic analyses of insulin biosynthesis in isolated rat and mouse islets.
Two RP-HPLC systems were developed for the separation of the products of the conversion of proinsulin into insulin in rat and mouse islets, including proinsulin I and II. Peaks were identified by microsequencing and radiosequencing. It was confirmed that mouse C-peptide I has a two amino acid deletion compared to rat C-peptide I. A marked species difference in the ratio between insulin I and II was observed, i.e., 2:1 in the rat and 1:2 in the mouse. Pulse-chase experiments in rat islets have demonstrated that the ratio between insulin I and II in newly synthesized insulin is higher than that of the stored insulin, indicating a slower conversion rate of proinsulin II compared to proinsulin I.
Linde
S
S
Hagedorn Research Laboratory, Gentofte, Denmark.
Nielsen
J H
JH
Hansen
B
B
Welinder
B S
BS
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D002096:C-Peptide / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007328:Insulin / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D007515:Islets of Langerhans / Q000378:metabolism*; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D011384:Proinsulin / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D002096:C-Peptide; D007328:Insulin; D011384:Proinsulin