James Arthur Hoffmann

Chemical, Physical, and Biologic Properties of Biosynthetic Human Insulin

Human insulin derived via recombinant DNA technology was tested extensively by a complex battery of analytic procedures. This product, which is designated biosynthetic human insulin, was found to be chemically, physically, and immunologically equivalent to pancreatic human insulin and biologically equivalent to both pancreatic human insulin and purified pork insulin.

Purification and analysis of the major components of chum salmon protamine contained in insulin formulations using high-performance liquid chromatography.

A simple high-performance liquid chromatographic method has been developed for the rapid purification and analysis of protamine components contained in insulin formulations. Only a single step is needed to separate peptides whose compositions, sizes, and unusual isoelectric points (pI 13.8) are nearly identical. The method involves their isocratic separation on a reversed-phase column using a pH 2 phosphate buffer and a low acetonitrile content as an eluant. The purified chum salmon components were analyzed by amino acid analysis, solid-phase amino acid sequencing, carboxypeptidase B digests, insulin complexation analysis, and a mass spectrophotometric procedure which gives an accurate mass of the intact peptides. This HPLC purification technique may also be applicable to protamines and other highly basic peptides isolated from other sources.

Single chain insulin with high bioactivity

The instant invention provides polypeptide compounds of the formula b-BP-a having significant insulin activity, nucleotide sequences encoding said polypeptides, vectors comprising said nucleotide sequences, and cell lines transformed with said vectors useful for treating diabetes.

Insulin and IGF-I Analogs: Novel Approaches to Improved Insulin Pharmacokinetics

Current insulin formulations do not mimic the normal glucose-induced release of insulin by the pancreas in a physiological manner.1 One limitation is the delayed absorption of hexameric insulin from the subcutaneous site of injection, such that soluble insulins (currently the most rapid acting formulations) are too slow and have too long a duration of action.2 Another limitation is that longer acting insulin formulations, such as human ultralente, exhibit too short a duration of action, show a pronounced peak in activity and are suspensions, resulting in variability in administration.3 The use of recombinant DNA technology and peptide chemistry have allowed the generation of insulin analogs with a wide variety of amino acid substitutions, which in turn halve been useful in mapping regions of the insulin nucleus that are associated with Zn2+ binding, dimer formation and insulin receptor interaction. This report will review the physical, biological and clinical characterization of several insulin analogs that have been designed to improve absorption characteristics and pharmacodynamics. Because of the structural homology between insulin and insulin-like growth factor-I (IGF-I), we have investigated specific IGF-like modifications in the insulin sequence to determine if these will transfer to pharmacokinetic differences in insulin absorption and clearance.