Two novel peptides were isolated from the crude venom of the social wasp Polybia paulista, by using RP-HPLC under a gradient of MeCN from 5 to 60% (v/v) and named Polybine-I and -II. Further purification of these peptides under normal phase chromatography, rendered pure enough preparations to be sequenced by Edman degradation chemistry. However, both peptides did not interact with phenylisothiocyanate reagent, suggesting the existence of a chemically blocked N-terminus. Therefore, the sequences of both peptides were assigned by ESI-MS/MS under CID conditions, as follows: Polybine-I Ac-SADLVKKIWDNPAL-NH2 (Mr 1610 Da) and Polybine-II Ac-SVDMVMKGLKIWPL-NH2 (Mr 1657 Da). During the tandem mass spectrometry experiments, a loss of 43 a.m.u. was observed from the N-terminal residue of each peptide, suggesting the acetylation of the N-terminus. Subsequently, the peptides with and without acetylation were synthesized on solid phase and submitted to functional characterizations; the biological activities investigated were: hemolysis, chemotaxis of polymorphonucleated leukocytes (PMNL), mast cell degranulation and antibiosis. The results revealed that the acetylated peptides exhibited more pronounced chemotaxis of PMNL cells and mast cell degranulation than the respective non-acetylated congeners; no hemolytic and antibiotic activities were observed, irrespective to the blockage or not of the alpha-amino groups of the N-terminal residues of each peptide. Therefore, the N-terminal acetylation may be related to the increase of the inflammatory activity of both peptides.
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http://dx.doi.org/10.1016/j.peptides.2004.08.019 | DOI Listing |
Diabetes Obes Metab
January 2025
School of Exercise and Health, Shanghai Frontiers Science Research Base of Exercise and Metabolic Health, Shanghai University of Sport, Shanghai, China.
Aims: To investigate the role of chemerin reduction in mediating exercise-induced Glucagon-like peptide-1 (GLP-1) secretion and the amelioration of pancreatic β-cell function in obesity.
Materials And Methods: Obesity models were established using wild-type and chemerin systemic knockout mice, followed by 8 weeks of moderate-intensity continuous aerobic exercise training. Serum chemerin levels, GLP-1 synthesis, glucose tolerance, pancreatic β-cell function, structure, and apoptosis were assessed.
J Am Soc Mass Spectrom
January 2025
MS Proteomics Research Group, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary.
In recent years, alternative enzymes with varied specificities have gained importance in MS-based bottom-up proteomics, offering orthogonal information about biological samples and advantages in certain applications. However, most mass spectrometric workflows are optimized for tryptic digests. This raises the questions of whether enzyme specificity impacts mass spectrometry and if current methods for nontryptic digests are suboptimal.
View Article and Find Full Text PDFClin Toxicol (Phila)
January 2025
Rocky Mountain Poison and Drug Safety Center, Denver, CO, USA.
Introduction: Glucagon-like peptide-1 agonists have gained attention in recent years due to their efficacy in managing type II diabetes mellitus and their emerging role in weight management. The purpose of this study was to characterize glucagon-like peptide-1 agonist exposures reported to a single United States regional poison center over nine years, including causes of exposure, associated clinical effects, and potential areas for improving patient education and safety.
Methods: This retrospective cohort study analyzed all poison center calls involving glucagon-like peptide-1 agonists submitted to a single United States regional poison center from 14 January 2014 to 1 May 2023.
Drug Des Devel Ther
January 2025
Department of Trauma Orthopedics, Affiliated Hospital of Jining Medical University, Jining, Shandong, 272007, People's Republic of China.
Purpose: Osteosarcoma (OS) is the most common malignant tumor associated with poor patient outcomes and a limited availability of therapeutic agents. Scutellarein (SCU) is a monomeric flavone bioactive compound with potent anti-cancer activity. However, the effects and mechanisms of SCU on the growth of OS remain unknown.
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