This study concerns the biosynthesis of a number of peptides in the neurointermediate lobe of the pituitary gland of the aquatic toad, Xenopus laevis. Using pulse-chase incubations in vitro and high-performance liquid chromatographic analysis, it could be shown that these peptides are synthesized through processing of a prohormone, pro-opiomelanocortin; all peptides were released into the incubation medium. On the basis of electrophoretic analysis, selective amino acid incorporation and immunoprecipitation, as well as peptide mapping by high-performance liquid chromatography, the peptides were classified into three distinct groups: two related to melanocyte-stimulating hormone (melanotropin), two related to adrenocorticotropic hormone (corticotropin) and two endorphin-like peptides. Using tryptic and chymotryptic maps of synthetic alpha-melanotropin and des-Ac alpha N-alpha-melanotropin as references, one of the melanotropin-like peptides was identified as des-Ac alpha N-alpha-melanotropin; the other one represents neither alpha-melanotropin nor any other known melanotropic peptide. The two peptides that were immunologically related to corticotropin had characteristics consistent with a structures resembling a peptide previously named 'corticotropin-like intermediate lobe peptide', corticotropin-(18-39). The two endorphin-like peptides, although highly related, do not have the same primary structure. In view of the apparent structural differences between the two peptides in each group, the possible occurrence of two prohormones is discussed.
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http://dx.doi.org/10.1111/j.1432-1033.1982.tb05840.x | DOI Listing |
ACS Infect Dis
January 2025
Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Mato Grosso do Sul 79117-900, Brazil.
Plants provide an abundant source of potential therapeutic agents, including a diverse array of compounds, such as cyclotides, which are peptides known for their antimicrobial activity. Cyclotides are multifaceted molecules with a wide range of biological activities. Their unique topology forms a head-to-tail cyclic structure reinforced by a cysteine knot, which confers chemical and thermal stability.
View Article and Find Full Text PDFDiabetes Care
February 2025
Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Objective: To provide an updated synthesis on effects of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) on weight, BMI, and waist circumference incorporating newer randomized controlled trials (RCTs), particularly in individuals with overweight or obesity.
Research Design And Methods: We systematically searched PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) for RCTs published from inception to 4 October 2024. The search was limited to RCTs evaluating the use of GLP-1 RAs for mean differences from baseline in weight, BMI, and waist circumference in adults with obesity or overweight with or without diabetes.
Acc Chem Res
January 2025
Department of Chemistry, Ben-Gurion University of the Negev, Be'er Sheva 84105, Israel.
ConspectusA key challenge in modern chemistry research is to mimic life-like functions using simple molecular networks and the integration of such networks into the first functional artificial cell. Central to this endeavor is the development of signaling elements that can regulate the cell function in time and space by producing entities of code with specific information to induce downstream activity. Such artificial signaling motifs can emerge in nonequilibrium systems, exhibiting complex dynamic behavior like bistability, multistability, oscillations, and chaos.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Anesthesiology and Surgical Intensive Care Unit, Xinhua Hospital, School of Medicine and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, People's Republic of China.
Identifying effective biomarkers has long been a persistent need for early diagnosis and targeted therapy of disease. While mass spectrometry-based label-free proteomics with trace cell has been demonstrated, deep proteomics with ultratrace human biofluid remains challenging due to low protein concentration, extremely limited patient sample volume, and substantial protein contact losses during preprocessing. Herein, we proposed and validated lanthanide metal-organic framework flowers (MOF-flowers), as effective materials, to trap and enrich protein in biofluid jointly through cation-π interaction and O-Ln coordination.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology (TUAT), 2-24-16 Naka-cho Koganei-shi, Tokyo 184-8588, Japan.
Nanopore sensing is widely used for single-molecule detection, originally applied to nucleic acids and now extended to protein sensing. Our study focuses on the complex conformational changes of peptides in nanopores, which may have implications for peptide fingerprinting and protein identification. Specifically, we investigated the interaction of a β-hairpin peptide (SV28) within an α-hemolysin (αHL) nanopore.
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