Glucagon-like peptide-1 (GLP-1) is an incretin hormone secreted by gastrointestinal L cells in response to nutrient ingestion Meier and Nauck (2005). It exerts numerous biological functions including stimulating glucose-dependent insulin secretion, inhibiting glucagon release, inducing satiety and slowing gastric emptying (Rajeev and Wilding, 2016). The physiological properties of GLP-1 render it as an ideal therapy for obesity and type 2 diabetes (T2D) (Rajeev and Wilding, 2016). However, native GLP-1 is not suitable for therapeutic use due to its short-circulating half-life (t1/2 < 2 min), which results mainly from rapid enzymatic inactivation by dipeptidyl peptidase-IV (DPP-IV), and/or rapid kidney clearance (Kieffer et al., 1995). In order to prolong the action of GLP-1, great efforts have been made in the past decade and two strategies are accessible: one is the use of DPP-IV inhibitors and the other is the development of DPPIV-resistant analog through structural modifications which prevent DPP-IV degradation (Drucker et al., 2010, 2011; Lindamood and Taylor, 2015; Lee, 2016; Rajeev and Wilding, 2016).