Stereorandomized Oncocins with Preserved Ribosome Binding and Antibacterial Activity.

We recently showed that solid-phase peptide synthesis using racemic amino acids yields stereorandomized peptides comprising all possible diastereomers as homogeneous, single-mass products that can be purified by HPLC and that stereorandomization modulates activity, toxicity, and stability of membrane-disruptive cyclic and linear antimicrobial peptides (AMPs) and dendrimers. Here, we tested if stereorandomization might be compatible with target binding peptides with the example of the proline-rich AMP oncocin, which inhibits the bacterial ribosome. Stereorandomization of up to nine -terminal residues preserved ribosome binding and antibacterial effects including activities against drug-resistant bacteria and protected against serum degradation.

An intrinsically disordered antimicrobial peptide dendrimer from stereorandomized virtual screening.

Membrane-disruptive amphiphilic antimicrobial peptides behave as intrinsically disordered proteins by being unordered in water and becoming α-helical in contact with biological membranes. We recently discovered that synthesizing the α-helical antimicrobial peptide dendrimer L- ((KL)(KL)(LL) KLL) using racemic amino acids to form stereorandomized -, an analytically pure mixture of all possible diastereoisomers of L-, preserved antibacterial activity but abolished hemolysis and cytotoxicity, pointing to an intrinsically disordered antibacterial conformation and an α-helical cytotoxic conformation. In this study, to identify non-toxic intrinsically disordered homochiral antimicrobial peptide dendrimers (AMPDs), we surveyed sixty-three -analogs of - selected by virtual screening.

Synergistic effects of antimicrobial peptide dendrimer-chitosan polymer conjugates against Pseudomonas aeruginosa.

We report herein a new chemical platform for coupling chitosan derivatives to antimicrobial peptide dendrimers (AMPDs) with different degrees of ramification and molecular weights via thiol-maleimide reactions. Previous studies showed that simple incorporation of AMPDs to polymeric hydrogels resulted in a loss of antibacterial activity and augmented cytotoxicity to mammalian cells. We have shown that coupling AMPDs to chitosan derivatives enabled the two compounds to act synergistically.

Machine learning designs non-hemolytic antimicrobial peptides.

Machine learning (ML) consists of the recognition of patterns from training data and offers the opportunity to exploit large structure-activity databases for drug design. In the area of peptide drugs, ML is mostly being tested to design antimicrobial peptides (AMPs), a class of biomolecules potentially useful to fight multidrug-resistant bacteria. ML models have successfully identified membrane disruptive amphiphilic AMPs, however mostly without addressing the associated toxicity to human red blood cells.

The antibacterial activity of peptide dendrimers and polymyxin B increases sharply above pH 7.4.

pH-activity profiling reveals that antimicrobial peptide dendrimers (AMPDs) kill Klebsiella pneumoniae and Methicillin-resistant Staphylococcus aureus (MRSA) at pH = 8.0, against which they are inactive at pH = 7.4, due to stronger electrostatic binding to bacterial cells at higher pH.

Discovery of a novel GLP-1/GIP dual receptor agonist CY-5 as long-acting hypoglycemic, anti-obesity agent.

Glucagon-like peptide-1 (GLP-1) receptor agonists as an effective approach for type 2 diabetes mellitus (T2DM) has been explored extensively, multi agonists based on GLP-1 may have better clinical benefits on obesity, Nonalcoholic steatohepatitis (NASH) and other metabolic diseases. To get multi agonists based on GLP-1, 15 conjugates were designed, synthesized, and tested for biological activity. GLP-1/glucagon dual receptor agonist E1 showed moderate long-acting hypoglycemic effect, CY-5 and CY-16 with GLP-1/GIP dual receptor agonistic activity exhibited longer duration of continuous blood glucose stabilization.

Synergistic Effect of Propidium Iodide and Small Molecule Antibiotics with the Antimicrobial Peptide Dendrimer G3KL against Gram-Negative Bacteria.

There is an urgent need to develop new antibiotics against multidrug-resistant bacteria. Many antimicrobial peptides (AMPs) are active against such bacteria and often act by destabilizing membranes, a mechanism that can also be used to permeabilize bacteria to other antibiotics, resulting in synergistic effects. We recently showed that , an AMP with a multibranched dendritic topology of the peptide chain, permeabilizes the inner and outer membranes of Gram-negative bacteria including multidrug-resistant strains, leading to efficient bacterial killing.

Novel glucagon- and OXM-based peptides acting through glucagon and GLP-1 receptors with body weight reduction and anti-diabetic properties.

Oxyntomodulin (OXM) is an endogenous gastrointestinal hormone, which activates both the Glucagon-like peptide-1 receptor (GLP-1R) and the glucagon receptor (GCGR). However, OXM has shortcomings including poor GLP-1R agonism to control glycemia, short half-life and others. Inspired from the sequence relationship between OXM and glucagon, in this study, we introduced different C-terminus residues of GLP-1, exenatide and OXM to glucagon to get a series of hybrid peptides with enhanced GLP-1R activation.

Novel lipid side chain modified exenatide analogs emerged prolonged glucoregulatory activity and potential body weight management properties.

Exenatide is known as the first marketed GLP-1 agonist for antidiabetic treatment, but it need twice injection a day because of its fast clearance. This work aims to prolong the half-life of exenatide by modified with novel lipid chain. Four optimized exenatide analogs named as Cys12-Exenatide (1-39)-NH, Cys40-Exenatide (1-39)-NH, Cys12-Tyr22-Gln24-Glu28-Arg35-Exenatide (1-39)-NH and Tyr22-Gln24-Glu28-Arg35-Cys40-Exenatide (1-39)-NH were selected and applied for conjugation.

Synthesis and evaluation of redox-sensitive gonadotropin-releasing hormone receptor-targeting peptide conjugates.

Lytic peptides have been demonstrated to exhibit obvious advantages in cancer therapy with binding ability toward tumor cells via electrostatic attractions, which are lack of active targeting and aggregation to tumor tissue. In the present study, five conjugated lytic peptides were redesigned and constructed to target gonadotropin releasing hormone receptors (GnRHr), meanwhile, the disulfide bridge was introduced to achieve redox sensitive delivery based on the experience from the preliminary work of lytic peptides P3 and P7. YX-1, was considered to be the most promising for in-depth study.

Synthesis and anti-cancer evaluation of folic acid-peptide- paclitaxel conjugates for addressing drug resistance.

The drug resistance and the poor water solubility are major limitations of paclitaxel (PTX) of based chemotherapy. To conquer the two problems, targeting folate (FA) receptor PTX-lytic peptides conjugates were synthesized and evaluated. Compared with PTX, FA-P3-PTX and FA-P7-PTX displayed significantly enhanced cell toxicity in many cancer cells, particularly drug resistant cancer cells MCF-7/PTX.

Novel nonapeptide GLP (28-36) amide derivatives with improved hypoglycemic and body weight lowering effects.

Glucagon-like peptide-1 (GLP-1) has emerged as a major therapeutic target for the treatment of type 2 diabetes. The nonapeptide GLP-1 (28-36) amide is one of the biological C-terminal products of GLP-1 modified by the neutral endopeptidase (NEP) 24.11 with limited hypoglycemic activity.

Novel fatty acid chain modified GLP-1 derivatives with prolonged in vivo glucose-lowering ability and balanced glucoregulatory activity.

Glucagon-like peptide-1 is a potent hypoglycemic hormone with beneficial properties for the treatment of diabetes. However, its half-life is short because the rapid metabolic degradation. This study aims to prolong the half-life of glucagon-like peptide-1 through conjugation with the fatty acid side chain which helps the conjugates to interact with the albumin.

Identification of highly potent and orally available free fatty acid receptor 1 agonists bearing isoxazole scaffold.

The free fatty acid receptor 1 (FFA1) is being considered to be a novel anti-diabetic target based on its role in amplifying insulin secretion. We have previously identified several series of FFA1 agonists with different heterocyclic scaffolds. Herein, we describe the structural exploration of other heterocyclic scaffolds directed by drug-like physicochemical properties.

Design, synthesis, and biological evaluation of deuterated phenylpropionic acid derivatives as potent and long-acting free fatty acid receptor 1 agonists.

The free fatty acid receptor 1 (FFA1) is a potential target due to its function in enhancement of glucose-stimulated insulin secretion. Takeda's compound 1 has robustly in vitro activity for FFA1, but it has been suffered from poor pharmacokinetic (PK) profiles because the phenylpropanoic acid is vulnerable to β-oxidation. To identify orally available agonists, we tried to interdict the metabolically labile group by incorporating two deuterium atoms at the α-position of phenylpropionic acid.

A novel glucagon-like peptide-1/glucagon receptor dual agonist exhibits weight-lowering and diabetes-protective effects.

Glucagon has plenty of effects via a specific glucagon receptor(GCGR) like elevating the blood glucose, improving fatty acids metabolism, energy expenditure and increasing lipolysis in adipose tissue. The most important role of glucagon is to regulate the blood glucose, but the emergent possibilities of hyperglycaemia is exist. Glucagon could also slightly activate glucagon-like peptide-1 receptor(GLP-1R), which lead to blood glucose lowering effect.

Pro-apoptotic cationic host defense peptides rich in lysine or arginine to reverse drug resistance by disrupting tumor cell membrane.

Host defense peptides have been demonstrated to exhibit prominent advantages in cancer therapy with selective binding ability toward tumor cells via electrostatic attractions, which can overcome the limitations of traditional chemotherapy drugs, such as toxicity on non-malignant cells and the emergence of drug resistance. In this work, we redesigned and constructed a series of cationic peptides by inserting hydrophobic residues into hydrophilic surface or replacing lysine (K) with arginine (R), based on the experience from the preliminary work of host defense peptide B1. In-depth studies demonstrated that the engineered peptides exhibited more potent anti-cancer activity against various cancer cell lines and much lower toxicity to normal cells compared with B1.

Design, synthesis and structure-activity relationship studies of novel free fatty acid receptor 1 agonists bearing amide linker.

The free fatty acid receptor 1 (FFA1/GPR40) has attracted extensive attention as a novel antidiabetic target. Aiming to explore the chemical space of FFA1 agonists, a new series of lead compounds with amide linker were designed and synthesized by combining the scaffolds of NIH screened lead compound 1 and GW9508. Among them, the optimal lead compound 17 exhibited a considerable agonistic activity (45.

Site-specific fatty chain-modified exenatide analogs with balanced glucoregulatory activity and prolonged in vivo activity.

The therapeutic utility of exenatide (Ex-4) is limited due to short plasma half-life of 2.4h and thus numerous approaches have been used to obtain a longer action time. However, such strategies often attend to one thing and lose another.

Discovery of novel pyrrole-based scaffold as potent and orally bioavailable free fatty acid receptor 1 agonists for the treatment of type 2 diabetes.

The free fatty acid receptor 1 (FFA1) has gained significant interest as a novel antidiabetic target. Most of FFA1 agonists reported in the literature bearing a common biphenyl scaffold, which was crucial for toxicity verified by the researchers of Daiichi Sankyo. Herein, we describe the systematic exploration of non-biphenyl scaffold and further chemical modification of the optimal pyrrole scaffold.

Coumaglutide, a novel long-acting GLP-1 analog, inhibits β-cell apoptosis in vitro and invokes sustained glycemic control in vivo.

Glucagon-like peptide-1 (GLP-1) is a potential candidate for the treatment of type 2 diabetes. However, native GLP-1 is not suitable for therapy of diabetes due to its short half-life (t1/2=2 min). Our recent discovery of the novel long-acting GLP-1 analog, coumaglutide, elicits favorable hypoglycemic effects.