Diabetes, Vol 46, Issue 4 637-642, Copyright © 1997 by American Diabetes Association
Acylation of human insulin with palmitic acid extends the time action of human insulin in diabetic dogs
SR Myers, FE Yakubu-Madus, WT Johnson, JE Baker, TS Cusick, VK Williams, FC Tinsley, A Kriauciunas, J Manetta and VJ Chen
Lilly Research Laboratories, Indianapolis, Indiana 46285, USA.
To test whether the binding of insulin to an endogenous serum protein can
be used to extend the time action of insulin, human insulin was acylated at
the epsilon-amino group of Lys(B29) with palmitic acid to promote binding
to serum albumin. Size-exclusion chromatography was used to demonstrate
specific binding of the resulting analog, [N(epsilon)-palmitoyl Lys(B29)]
human insulin, to serum albumin in vitro, and the time action and activity
of the analog were determined in vivo using overnight-fasted,
insulin-withdrawn diabetic dogs. In the diabetic animal model, the duration
of action of [N(epsilon)-palmitoyl Lys(B29)] human insulin administered
intravenously was nearly twice that of unmodified human insulin, and the
plasma half-life was nearly sevenfold that of the unmodified protein.
Administered subcutaneously, [N(epsilon)-palmitoyl Lys(B29)] human insulin
had a longer duration of action; a flatter more basal plasma insulin
profile; and a lower intersubject variability of response than the
intermediate-acting insulin suspension Humulin L (Lilly, Indianapolis, IN).
These studies support the concept that modification of insulin to promote
binding to an existing serum protein can be used to extend the time action
of human insulin. In addition, the time action, pattern, and decreased
variability of response to [N(epsilon)-palmitoyl Lys(B29)] human insulin
support the development and further testing of this soluble insulin analog
as a basal insulin to increase the safety of intensive insulin therapy.