Sensitive RIA for the specific determination of insulin lispro.
Insulin lispro is an insulin analog in which the primary sequence has been altered by the inversion of amino acids B28 and B29. To date, it has not been possible to specifically measure insulin lispro in the presence of endogenous insulin because of the high degree of homology between these peptides. However, the specific determination of insulin lispro offers advantages over quantifying total concentrations of immunoreactive insulin. We therefore immunized guinea pigs and screened for antibodies with increased affinity and selectivity for insulin lispro. We prepared a monospecific antiserum by a novel immunoadsorption strategy using despentapeptide insulin. The antiserum was used to develop a competitive RIA for insulin lispro. The RIA has a low limit of quantification (17.2 pmol/L); has no interference from insulin, proinsulin, or C-peptide; and has interassay CVs of 2.6-13.4%. The new RIA is useful for measuring serum concentrations of insulin lispro.
Bowsher
R R
RR
Department of Drug Disposition, Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN 46285, USA. bowsher_ronald_r@lilly.com
Lynch
R A
RA
Brown-Augsburger
P
P
Santa
P F
PF
Legan
W E
WE
Woodworth
J R
JR
Chance
R E
RE
D000595:Amino Acid Sequence; D000818:Animals; D002138:Calibration; D003429:Cross Reactions; D004355:Drug Stability; D006168:Guinea Pigs; D006801:Humans; D007004:Hypoglycemic Agents / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D007106:Immune Sera; D007114:Immunization; D007328:Insulin / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry / Q000276:immunology; D061268:Insulin Lispro; D008969:Molecular Sequence Data; D011384:Proinsulin / Q000097:blood; D011863:Radioimmunoassay; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007004:Hypoglycemic Agents; D007106:Immune Sera; D007328:Insulin; D061268:Insulin Lispro; D011384:Proinsulin