Abstract
The insulin self-association and dissociation is an important trend in drug discovery studies and insulin structural-activity optimizations. Currently, little is known about the structural basis of insulin activity in animals in general and specifically camels for their unique glycemic status. To fill a knowledge gap in insulin molecular aspects in animals and their future application in human medicine, this research used a structural analysis method that included protein sequence panel comparison followed by molecular dynamics studies. The identity% with human insulin was in the following order swine=rabbit>bovine=ovine>camel with amino acid differences range from 1-4 residues. The residue scanning and mutation of the B chain residue T30 in human insulin to the alanine residue in bovine, camel, and ovine insulin resulted in decreased insulin dimer affinity and stability with Delta stability equals 3.94, 8.43 and 8.43, respectively. The camel insulin showed the highest conformational changes, retarded arrival to the steady state of residues deviation, the most prominent asymmetric monomer fluctuations, the shortest distance between the insulin-stabilizing cysteines disulfide bonds and less conformationally stable insulin monomer 2. The camel insulin dimer is expected to be more dissociable to yield active monomers and to lesser extent swine, bovine and ovine dimers. In addition, the camel monomer is stabilized by the stronger inter-chains cysteines recognition. The merit of residue mutation at dimer interface to mimic the B-chain T30 from camel, swine, and bovine insulin might help in improving the human insulin dimer dissociation and hence the shorter duration to release the active insulin monomer.