A novel insulin derivative chemically modified with dehydrocholic acid: synthesis, characterization and biological activity.
A novel chemically modified insulin, -NB29-DHC-insulin (where DHC-insulin stands for dehydrocholyl-insulin), was prepared by covalent linkage of DHC (dehydrocholic acid) to the -amino group of LysB29 without any protecting agent and analysed by PAGE and reversed-phase HPLC. DHC-insulin was identified by MALDI-TOF-MS (matrix-assisted laser-desorption ionization-time-of-flight MS) coupled with dithiothreitol and trypsin treatment. The major product, mono-DHC-insulin, was -NB29-DHC-insulin. The biological activity of the modified insulin was evaluated by measuring the in vivo hypoglycaemic effect and in vitro tryptic degradation. Mono-DHC-insulin maintained the glucose-lowering effect as strongly as native insulin, showed a significantly slower disappearance due to an increase of its receptor-binding potency and retained approx. 40% of the reduced glucose relative to the undegraded sample digested for 6 h with trypsin in vitro. These results suggested that -NB29-DHC-insulin showed a longer duration of action compared with native insulin and also a protective effect from tryptic degradation.
Huang
Tao
T
Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Huang
Kaixun
K
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism*; D003685:Dehydrocholic Acid / Q000737:chemistry*; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000138:chemical synthesis; D007279:Injections, Subcutaneous; D007328:Insulin / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D008297:Male; D008657:Metabolic Clearance Rate / Q000187:drug effects; D051379:Mice
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D003685:Dehydrocholic Acid