ImKTx96, a peptide blocker of the Kv1.2 ion channel from the venom of the scorpion Isometrus maculates
In this study, we characterized a K+-channel toxin gene, ImKTx96, from the venom gland cDNA library of the scorpion Isometrus maculates. The peptide deduced from the ImKTx96 precursor nucleotide sequence contains a signal peptide of 27 amino acid residues and a mature peptide of 29 residues with three disulfide bridges. Multiple sequence alignment indicated that ImKTx96 is similar with the scorpion toxins that typically target K+-channels. The recombined ImKTx96 peptide (rImKTx96) was expressed in the Escherichia coli system, and purified by GST-affinity chromatography and RP-HPLC. Results from whole-cell patch-clamp exper...
Source: Peptides - October 16, 2019 Category: Biochemistry Source Type: research

Design and Evaluation of Four Novel Tripeptides as Potent Angiotensin Converting Enzyme (ACE) inhibitors with Anti-hypertension Activity
Publication date: Available online 12 October 2019Source: PeptidesAuthor(s): Bingjun Qian, Chongchong Tian, Jianghua Huo, Zhiwen Ding, Ran Xu, Juan Zhu, Lili Yu, Oscar D. VillarrealAbstractThe current study investigated the angiotensin-converting enzyme (ACE) inhibitory activity of 4 synthetic tripeptides. All the peptides showed enzyme inhibitory activity, especially two promising ones, TTP (Thea-Thea-Pro) and gAgAP (GABA-GABA-Pro), with IC50 values of 0.92 and 3.4⿿μmol/L, respectively. Enzyme inhibition kinetics determined by Lineweaver-Burk plots revealed that TTP and gAgAP were competitive inhibitors with Ki values ...
Source: Peptides - October 13, 2019 Category: Biochemistry Source Type: research

The early history of GIP 1969–2000: From enterogastrone to major metabolic hormone
Publication date: December 2019Source: Peptides, Volume 122Author(s): Vincent MarksAbstractThis paper describes the early history of Gastric Inhibitory Polypeptide, better referred to simply as GIP, from its isolation by purification from a crude preparation of CCK-PZ (cholecystokinin/pancreozymin) to its recognition as a key player in the pathogenesis of obesity and other metabolic disorders far removed from the enterogastrone properties by which it was originally identified. Augmentation of glucose mediated insulin release, the incretin effect, was discovered soon after GIP was first isolated and only much later was its ...
Source: Peptides - October 5, 2019 Category: Biochemistry Source Type: research

Molecular evolution of GIP and Exendin and their receptors
Publication date: Available online 30 September 2019Source: PeptidesAuthor(s): David M. IrwinAbstractGlucose-dependent insulinotropic polypeptide (GIP) is a product of the Gip gene and acts as an incretin hormone in mammals. Gip is most closely related to the proglucagon (Gcg) and Exendin genes and diverged from these very early in vertebrate evolution. In mammals, GIP acts through its specific receptor, encoded by the Gipr gene, which belongs to a subfamily of 7-transmembrane G-protein coupled receptor (GPCR) genes that also includes those for the proglucagon-derived peptides (Gcgr, Glp1r, and Glp2r), and the receptor for...
Source: Peptides - October 1, 2019 Category: Biochemistry Source Type: research

Potential role of natural bioactive peptides for development of cosmeceutical skin products
Publication date: Available online 28 September 2019Source: PeptidesAuthor(s): J.E. Aguilar-Toalá, A. Hernández-Mendoza, A.F. González-Córdova, B. Vallejo-Cordoba, A.M. LiceagaAbstractIn recent years, consumers’ demand for cosmeceutical products with protective and therapeutic functions derived from natural sources have caused this industry to search for alternative active ingredients. Bioactive peptides have a wide spectrum of bioactivities, which make them ideal candidates for development of these cosmeceutical products. In vitro studies have demonstrated that bioactive peptides (obtained as extracts, hydrolysates,...
Source: Peptides - September 30, 2019 Category: Biochemistry Source Type: research