Engineered insulins

Faster-Acting Insulin Genetic Engineering Solves a Qjiaternary Structure Problem... 

Recombinant DNA technology now verges on the ability to engineer at will the genetic constitution of organisms for desired ends. The commercial production of therapeutic biomolecules in microbial cultures is already established (for example, the production of human insulin in quantity in E. coli cells). Agricultural crops with desired attributes, such as enhanced resistance to her-... 

Insulin is one of the important pharmaceutical products produced commercially by genetically engineered bactera. Before this development, commercial insulin was isolated from animal pancreatic tissue. Microbial insulin has been available since 1982. The human insulin gene is introduced into a bacterium like E. coli. Two of the major advantages of insulin production by microorganisms are that the resultant insulin is chemically identical to human insulin, and it can be produced in unlimited quantities. 

Many of the initial biopharmaceuticals approved were simple replacement proteins (e.g. blood factors and human insulin). The ability to alter the amino acid sequence of a protein logically coupled to an increased understanding of the relationship between protein structure and function (Chapters 2 and 3) has facilitated the more recent introduction of several engineered therapeutic proteins (Table 1.3). Thus far, the vast majority of approved recombinant proteins have been produced in the bacterium E. coli, the yeast S. cerevisiae or in animal cell lines (most notably Chinese hamster ovary (CHO) cells or baby hamster kidney (BHK) cells. These production systems are discussed in Chapter 5. 

The biopharmaceutical sector is largely based upon the application of techniques of molecular biology and genetic engineering for the manipulation and production of therapeutic macromolecules. The majority of approved biopharmaceuticals (described from Chapter 8 onwards) are proteins produced in engineered cell lines by recombinant means. Examples include the production of insulin in recombinant E. coli and recombinant S. cerevisiae, as well as the production of EPO in an engineered (Chinese hamster ovary) animal cell line. 

The expression of recombinant proteins in cells in which they do not naturally occur is termed heterologous protein production (Chapter 3). The first biopharmaceutical produced by genetic engineering to gain marketing approval (in 1982) was recombinant human insulin (tradename Humulin ), produced in E. coli. An example of a more recently approved biopharmaceutical that is produced in E. coli is that of Kepivance, a recombinant keratinocyte growth factor used to treat oral mucositis (Chapter 10). Many additional examples are provided in subsequent chapters. 

Novolog Engineered short-acting insulin Diabetes mellitus 11... 

Human insulin produced by recombinant DNA technology was first approved for general medical use in 1982, initially in the USA, West Germany, the UK and The Netherlands. As such, it was the first product of recombinant DNA technology to be approved for therapeutic use in humans. From the 1990s on, several engineered insulin products (discussed later) also gained approval (Table 11.3). 

Table 11.3 Native and engineered human insulin preparations that have gained approval for general medical use. Reproduced in updated form with permission from Walsh, G. 2005. Therapeutic insulins and their large-scale manufacture. Applied Microbiology and Biotechnology, 67, 151-159...

Humalog (Insulin lispro) Recombinant short-acting human insulin analogue produced in E. coli Engineered inversion of native B28-B29 proline-lysine sequence Eli Lilly 1996 (USA and EU)... 

NovoRapid (Insulin Aspart) Recombinant shortacting human insulin analogue produced in S. cerevisiae Engineered B28 proline replaced by aspartic acid Novo Nordisk 1999 (EU)... 

Apidra (Insulin Recombinant rapid- Engineered B3 asparagine Aventis 2004... 

Lantus (Insulin Recombinant long-acting Engineered A 21 asparagine Aventis 2000 (USA... 

Recombinant DNA technology facilitates not only production of human insulin in microbial systems, but also facilitates generation of insulins of modified amino acid sequences. The major aims of generating such engineered insulin analogues include ... 

---