The engineering of antigenic determinants on super secondary structures using de novo design approaches often involves synthesis of long peptide chains (35-80 residues long). This communication illustrates that the stabilization of secondary structure by rational design can also greatly enhance immunogenicity and antigenicity, but in much shorter peptide sequences (21 residues long). A peptide epitope the sequence of which has been derived from the C-terminus of the chicken riboflavin carrier protein (cRCP), H2N-Tyr-His-Ala-Cys-Gln-Lys-Lys-Leu-Leu- Lys-Phe-Glu-Ala-Leu-Gln-Gln-Glu-Glu-Gly-Glu-Glu-OH, has been chosen for analysis. Helical conformations were induced in the peptide in aqueous trifluoroethanol. Analogs were designed to stabilize this conformation in water by either the introduction of appropriately spaced ion pairs or the strongly helix nucleating residue alpha-aminoisobutyric acid (Aib), substituted for Ala/Gly, thus affording a comparison of the helix stabilization strategies. Circular dichroism (CD) results demonstrate that all the designed analogs are appreciably more helical than the parent peptide in 50% aqueous trifluoroethanol. Peptide antisera were raised for all analogs in rabbits. The affinities of these antisera for the native protein antigen, determined using a chaotrope disrupted binding assay, correlated very well with the helix content determined by CD.
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http://dx.doi.org/10.1016/0014-5793(95)00166-7 | DOI Listing |
Food Chem
January 2025
Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA. Electronic address:
Food allergens are defined by their stability during digestion, with allergenicity largely influenced by resistance to enzymatic hydrolysis. Ovalbumin (OVA), a major egg protein, is a significant contributor to food allergies, particularly in children. Our previous work demonstrated that high hydrostatic pressure (HHP) treatment reduces OVA allergenicity by disrupting conformational epitopes and altering its structure.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
The microbial aminotransferase enzyme DapC is vital for lysine biosynthesis in various Gram-positive bacteria, including . Characterization of the enzyme's conformational dynamics and identifying the key residues for ligand binding are crucial for the development of effective antimicrobials. This study employs atomistic simulations to explore and categorize the dynamics of DapC in comparison to other classes of aminotransferase.
View Article and Find Full Text PDFBiochemistry
January 2025
Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa.
C-terminal amidation of antimicrobial peptides (AMPs) is a frequent minor modification used to improve antibacterial potency, commonly ascribed to increased positive charge, protection from proteases, and a stabilized secondary structure. Although the activity of AMPs is primarily associated with the ability to penetrate bacterial membranes, hitherto the effect of amidation on this interaction has not been understood in detail. Here, we show that amidation of the scorpion-derived membranolytic peptide AamAP1-Lys produces a potent analog with faster bactericidal activity, increased membrane permeabilization, and greater Gram-negative membrane penetration associated with greater conformational flexibility.
View Article and Find Full Text PDFEur Heart J Case Rep
January 2025
Department of Cardiology, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-Ku, Yokohama city, Kanagawa 236-0004, Japan.
Background: Coronary sinus (CS) lead placement in persistent left superior vena cava (PLSVC) cases is challenging because of the poor backup force of the guiding catheter within the enlarged CS. Active fixation Quadripolar leads (Attain Stability™ Quad 4798, Medtronic) can expand choice to CS branches with limited access; however, no cases of anchoring to the main body of the CS have been published to date.
Case Summary: We describe a case of cardiac resynchronization therapy pacemaker upgrade in a 79-year-old female who developed pacing-induced cardiomyopathy after pacemaker implantation via the right superior vena cava (SVC) for atrioventricular block eight years ago wherein PLSVC was revealed during the procedure.
Soft Matter
January 2025
College of Chemistry, Sichuan University, Chengdu 610064, China.
Biomolecules usually adopt ubiquitous circular structures which are important for their functionality. Based on three-dimensional Langevin dynamics simulations, we investigate the conformational change of a polymer confined in a spherical cavity. Both passive and active polymers with either homogeneous or heterogeneous stiffness are analyzed in a comparative manner.
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