The depsipeptide Boc(1)-Leu(2)-Leu(3)-Ala(4)-Leu(5)-Leu(6)-Lac(7)-Leu(8)-Leu(9)-Lac(10)-Leu(11)-Leu(12)-Lac(13)-Leu(14)-Leu(15)-OEt(16) (1) (Boc = tert-butyloxycarbonyl, Lac = L-lactic acid residue) has been synthesized from the peptide Boc-Leu-Leu-Ala-OEt (2) and a depsipeptide, Boc-(Leu-Leu-Lac)(3)-Leu-Leu-OEt (3). Single crystals of 1 were successfully obtained and the structure has been solved by direct methods (such as Sir2002 and Shake-and-Bake). Interestingly, 1 adopts an alpha/3(10)-conjugated helix containing a kink at the junction of peptide and depsipeptide segments, Leu3-Lac7. This is significantly different from the conformation of 3, which has a straight alpha-helical structure with standard phi and psi angles. Microcrystalline CD spectra were also studied to compare structural properties of 1 and 3. The differences between alpha/3(10)- and alpha-helices appear in these CD spectra.
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http://dx.doi.org/10.1002/bip.20117 | 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 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 PDFJ Phys Chem B
January 2025
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Computationally designed 29-residue peptides yield tetra-α-helical bundles with symmetry. The "bundlemers" can be bifunctionally linked via thiol-maleimide cross-links at their N-termini, yielding supramolecular polymers with unusually large, micrometer-scale persistence lengths. To provide a molecularly resolved understanding of these systems, all-atom molecular modeling and simulations of linked bundlemers in explicit solvent are presented.
View Article and Find Full Text PDFCurr Res Food Sci
January 2025
School of Biological and Chemical Engineering, Guangxi University of Science and Technology, Guangxi Key Laboratory of Green Processing of Sugar Resources, Key Laboratory for Processing of Sugar Resources of Guangxi Higher Education Institutes, Liuzhou, 545006, China.
The combination of polyphenols and protein can improve the functional characteristics of protein. How to effectively promote the binding of polyphenols to protein is still a difficult topic. In this study, hydrodynamic cavitation (HC) was used to induce the fabrication of complexes between soy protein isolate (SPI) and different polyphenols (tannic acid (TA), chlorogenic acid (CGA), ferulic acid (FA), caffeic acid (CA), and gallic acid (GA)).
View Article and Find Full Text PDFCytotechnology
April 2025
Child Rehabilitation Department, Hubei NO.3 People's Hospital of Jianghan University, No. 26 Zhongshan Avenue, Qiaokou District, Wuhan, 430033 China.
Unlabelled: Inflammatory bowel disease (IBD) is a chronic, progressive, immune-mediated, gastrointestinal inflammatory disease with increasing occurrences in children. Collagen triple helix repeat containing 1 (CTHRC1), a migration-promoting protein, acts as a tumor-promoting factor in malignant tumors. However, functions and mechanisms of CTHRC1 in children with IBD remain unclear.
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