Table 1.

Recombinant insulins approved for human use.

INN1	Trade name	Production system	Modifications from natural	PK2
Insulin human	Humulin Insuman Exubera3	E. coli	None	Short-acting insulin
Insulin human	Novolin	S. cerevisiae	None	Short-acting insulin
Insulin lispro	Humalog	E. coli	PB28K and KB29P	Rapid-acting insulin analogue
Insulin glulisine	Apidra	E. coli	NB3K and KB29E	Rapid-acting insulin analogue
Insulin aspart	Novorapid	S. cerevisiae	DB28P	Rapid-acting insulin analogue
Insulin glargin	Lantus	E. coli	NA21G and 2 additional R in B chain	Long-acting insulin analogue
Insulin detemir	Levemir	S. cerevisiae	TB30del and myristic fatty acid attached to KB29 by acylation	Long-acting insulin analogue

Insulin is a polypeptide of 51 amino acid, 30 of which constitute A chain, and 21 of which comprise B chain. The two chains are linked by a disulfide bond. Mutations in amino acid sequences are noted for each of the chains.

¹INN: International Nonproprietary Names. ²PK:PharmacoKinetics. ³Exubera: Rapid-actin insulin using inhalation route [17], was discontinued in 2008 by the manufacturer