Sarcotoxin IA is a 39-residue cecropin-type peptide from Sarcophaga peregrina. This peptide exhibits antibacterial activity against Gram-negative bacteria through its interaction with lipid A, a core component of lipopolysaccharides. To acquire detailed structural information on this specific interaction, we performed NMR analysis using bacterially expressed sarcotoxin IA analogs with (13)C- and (15)N-labeling along with lipid A-embedding micelles composed of dodecylphosphocholine. By inspecting the stable isotope-assisted NMR data, we revealed that the N-terminal segment (Leu3-Arg18) of sarcotoxin IA formed an amphiphilic α-helix upon its interaction with the aqueous micelles. Furthermore, chemical shift perturbation data indicated that the amino acid residues displayed on this α-helix were involved in the specific interaction with lipid A. On the basis of these data, we successfully identified Lys4 and Lys5 as key residues in the interaction with lipid A and the consequent antibacterial activity. Therefore, these results provide unique information for designing chemotherapeutics based on antibacterial peptide structures.
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http://dx.doi.org/10.1016/j.bbrc.2013.01.009 | DOI Listing |
Biophys J
January 2025
Department of Biology, New York University, New York, New York, 10003, USA. Electronic address:
The outer membrane is the defining structure of Gram-negative bacteria. We previously demonstrated that it is a major load-bearing component of the cell envelope and is therefore critical to the mechanical robustness of the bacterial cell. Here, to determine the key molecules and moieties within the outer membrane that underlie its contribution to cell envelope mechanics, we measured cell-envelope stiffness across several sets of mutants with altered outer-membrane sugar content, protein content, and electric charge.
View Article and Find Full Text PDFLipids Health Dis
January 2025
Department of Neurosurgery, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, 213000, China.
Background: Stroke has emerged as an escalating public health challenge among middle-aged and older individuals in China, closely linked to glycolipid metabolic abnormalities. The Hemoglobin A1c/High-Density Lipoprotein Cholesterol (HbA1c/HDL-C) ratio, an integrated marker of glycolipid homeostasis, may serve as a novel predictor of stroke risk.
Methods: Our investigation utilized data from the China Health and Retirement Longitudinal Study cohort (2011-2018).
BMC Genomics
January 2025
Henan Collaborative Innovation Center of Modern Biological Breeding, College of Agronomy, Henan Institute of Science and Technology, Xinxiang, 453003, China.
Background: The Sec14 domain is an ancient lipid-binding domain that evolved from yeast Sec14p and performs complex lipid-mediated regulatory functions in subcellular organelles and intracellular traffic. The Sec14 family is characterized by a highly conserved Sec14 domain, and is ubiquitously expressed in all eukaryotic cells and has diverse functions. However, the number and characteristics of Sec14 homologous genes in soybean, as well as their potential roles, remain understudied.
View Article and Find Full Text PDFSci Rep
January 2025
Division of Hematology, Second Xiang-ya Hospital, Central South University, Changsha, China.
Acute B-lymphoblastic leukemia (B-ALL) is a highly heterogeneous hematologic malignancy, characterized by significant molecular differences among patients as the disease progresses. While the PI3K-Akt signaling pathway and metabolic reprogramming are known to play crucial roles in B-ALL, the interactions between lipid metabolism, immune pathways, and drug resistance remain unclear. In this study, we performed multi-omics analysis on different patient cohorts (newly diagnosed, relapsed, standard-risk, and poor-risk) to investigate the molecular characteristics associated with metabolism, signaling pathways, and immune regulation in B-ALL.
View Article and Find Full Text PDFMetabolomics
January 2025
Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Background: Gestational exposure to non-persistent endocrine-disrupting chemicals (EDCs) may be associated with adverse pregnancy outcomes. While many EDCs affect the endocrine system, their effects on endocrine-related metabolic pathways remain unclear. This study aims to explore the global metabolome changes associated with EDC biomarkers at delivery.
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