Probing the correlation between insulin activity and structural stability through introduction of the rigid A6–A11 bond

Ong, Shee Chee; Belgi, Alessia; Lierop, Bianca J. van; Delaine, Carlie; Andrikopoulos, Sof; MacRaild, Christopher A.; Norton, Raymond S.; Haworth, Naomi L.; Robinson, Andrea J.; Forbes, Briony E.

doi:10.1074/jbc.ra118.002486

Cited by 10 publications

(12 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The A6-A11 loop is on the opposite side of insulin to the site 2 binding region and HisB10 is peripheral to this binding site (15)(16)(17). However, a bulge introduced in the cisdicarba insulin B chain close to site 2 residue LeuB17 may impact site 2 binding (30). Study of cis-dicarba dissociation kinetics and determination of a structure of the dicarba insulin: IR-A complex would reveal any impact on the Fn-III-1' interaction and is in future plans.…”

Section: Discussionmentioning

confidence: 99%

Minimizing Mitogenic Potency of Insulin Analogues Through Modification of a Disulfide Bond

et al. 2022

Self Cite

View full text Add to dashboard Cite

The mechanisms by which insulin activates the insulin receptor to promote metabolic processes and cellular growth are still not clear. Significant advances have been gained from recent structural studies in understanding how insulin binds to its receptor. However, the way in which specific interactions lead to either metabolic or mitogenic signalling remains unknown. Currently there are only a few examples of insulin receptor agonists that have biased signalling properties. Here we use novel insulin analogues that differ only in the chemical composition at the A6–A11 bond, as it has been changed to a rigid, non-reducible C=C linkage (dicarba bond), to reveal mechanisms underlying signaling bias. We show that introduction of an A6-A11 cis-dicarba bond into either native insulin or the basal/long acting insulin glargine results in biased signalling analogues with low mitogenic potency. This can be attributed to reduced insulin receptor activation that prevents effective receptor internalization and mitogenic signalling. Insight gained into the receptor interactions affected by insertion of an A6-A11 cis-dicarba bond will ultimately assist in the development of new insulin analogues for the treatment of diabetes that confer low mitogenic activity and therefore pose minimal risk of promoting cancer with long term use.

show abstract

Section: Discussionmentioning

confidence: 99%

Minimizing Mitogenic Potency of Insulin Analogues Through Modification of a Disulfide Bond

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…This kind of conformational transitions and partial unfolding of the protein was also evidenced in the process of its receptor binding. 12,17 Once released into blood circulation, HI molecules are exposed to undergo dynamic structural transitions from a hexameric form to biologically active monomer 18 in response to changes in its concentration, physiological pH as well as allosteric ligands. One of the key determinants to maintain structural stability and function of the HI molecule is to maintain the integrity of helical folds during structural transitions and unfolding steps of HI B chain.…”

Section: Introductionmentioning

confidence: 99%

Mechanistic Studies of the Stabilization of Insulin Helical Structure by Coomassie Brilliant Blue

Dolui¹,

Pariary

Saha³

et al. 2020

Preprint

View full text Add to dashboard Cite

Human insulin (HI) is an essential protein hormone and its biological activity mostly depends on folded and active conformation in the monomeric state. The present investigation established that Coomassie Brilliant Blue G-250 (CBBG), a small multicyclic hydroxyl compound can reversibly bind to the hormonal protein dimer and maintained most of α-helical folds crucial for biological function of the enzyme. The solution-state 1D NMR and isothermal calorimetric analysis showed a sub-micromolar binding affinity of the molecule to HI. 2D NOESY NMR established that the HI dimer undergoes residue level local conformational change upon binding to CBBG. The chemical shift perturbation and the NOE parameters of active protons of amino acid residues throughout the polypeptides further suggested that CBBG upon binding the protein stabilize α-helixes of both the A and B subunits of the hormonal protein. The changes in Gibb’s free energy (∆G) of the binding was of ~−11.1 kcal/mol and suggested a thermodynamically favourable process. The changes in enthalpy (∆H) and entropy term (T∆S) were −57.2 kcal/mol and −46.1 kcal/mol, respectively. The negative changes in entropy and the NOE transfer effectiveness of several residues in the presence of CBBG molecules indicated that the binding was an enthalpy driven favourable equilibrium process. The NMR-based atomic resolution data and molecular docking studies confirmed that the CBBG binds to HI at the dimeric stage and prevents the availability of the crucial residue segments that partake directly in further oligomerization and subsequent fibrillation. Extended computational analysis based on chemical shift perturbation of protons of active residues further established receptor-ligand based pharmacophore model comprised of 5 hydrophobic and a hydrogen bond acceptor features that can anchor the residues at the A and B chains of HI and inhibit the partial unfolding and hydrophobic collapse to nucleate the fibrillation. Taken together, the results demonstrated that CBBG and their close analogues might be useful to develop a formulation that will maintain the active and functional form of the hormonal protein for a significantly longer time.TOC

show abstract

“…However, the introduced disulfide mimetics may influence insulin bioactivity depending on the extent of the structural perturbation . Among the reported studies, insulin analogues with A6-A11 thioether, A6-A11 cis -dicarba or A6-A11, and A7-B7 diselenide bond replacement preserved insulin bioactivity. On the other hand, replacements involving A7-B7 triazole or A6-A11 trans -dicarba resulted in reduced potency (Figure D).…”

Section: Introductionmentioning

confidence: 99%

“…Among the reported studies, insulin analogues with A6-A11 thioether, A6-A11 cis -dicarba or A6-A11, and A7-B7 diselenide bond replacement preserved insulin bioactivity. On the other hand, replacements involving A7-B7 triazole or A6-A11 trans -dicarba resulted in reduced potency (Figure D). While these analogues have some desired properties, non-natural amino acids are required, which makes practical applications challenging.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of an A6-A11 Methylene Thioacetal Human Insulin Analogue with Enhanced Stability

et al. 2019

View full text Add to dashboard Cite

Insulin has been a life-saving drug for millions of people with diabetes. However, several challenges exist which limit therapeutic benefits and reduce patient convenience. One key challenge is the fibrillation propensity, which necessitates refrigeration for storage. To address this limitation, we chemically synthesized and evaluated a methylene thioacetal human insulin analogue (SCS-Ins). The synthesized SCS-Ins showed enhanced serum stability and aggregation resistance while retaining bioactivity compared with native insulin.

show abstract

Probing the correlation between insulin activity and structural stability through introduction of the rigid A6–A11 bond

Cited by 10 publications

References 59 publications

Minimizing Mitogenic Potency of Insulin Analogues Through Modification of a Disulfide Bond

Minimizing Mitogenic Potency of Insulin Analogues Through Modification of a Disulfide Bond

Mechanistic Studies of the Stabilization of Insulin Helical Structure by Coomassie Brilliant Blue

Synthesis and Characterization of an A6-A11 Methylene Thioacetal Human Insulin Analogue with Enhanced Stability

Contact Info

Product

Resources

About