Rational design and evaluation of GLP-1 derivative for treating hyperglycemia combined with overexercise-induced myocardial injury.

AIMS: To design and evaluate the anti-hyperglycemia and overexercise-induced myocardial injury efficacies of a novel long-acting glucagon-like peptide-1 (GLP-1)-based therapeutic peptide in rodent animals. MAIN METHODS: Here, we designed and prepared a new pro-drug, termed RYHSB-1, which was connected by a mutated GLP-1(A8G) and an albumin binding peptide via a protease-cleavable linker. Moreover, isothermal titration calorimetry (ITC) was applied to detect its binding affinity for HSA. GLP-1 release assay was conducted in mouse serum in vitro and quantified using LC-MS/MS method. Modified intraperitoneal glucose tolerance test (IPGTT), chronic efficacies study in rodent animals with overexercise-induced myocardial injury were subjected to evaluate the druggability of RYHSB-1. RESULTS: RYHSB-1 with purity over 99% was prepared and ITC measurement demonstrated high binding affinity for HSA with KD of 0.06 μM. Protease cleavage assay demonstrated slowly controlled-release of transient GLP-1 from RYHSB-1 under the hydrolysis catalyzed by thrombin in vitro. Moreover, IPGTT showed clearly dose-dependent glucose-lowering efficacies of RYHSB-1 within 0.1-0.9 mg/kg. The prolonged anti-diabetic efficacy of RYHSB-1 was further assessed via multiple IPGTTs and hypoglycemic duration test. Furthermore, long-term administration of RYHSB-1 in diabetic mice achieved promising efficacies on hyperglycemia and overexercise-induced myocardial injury. SIGNIFICANCE: RYHSB-1 holds outstanding pharmaceutical potential as an anti- overexercise-induced myocardial injury drug. The strategy of albumin-conjugation also could be applied to other active peptides develop long effecting therapeutic drugs.