Here we uncover collagen, the main structural protein of all connective tissues, as a redox-active material. We identify dihydroxyphenylalanine (DOPA) residues, post-translational oxidation products of tyrosine residues, to be common in collagen derived from different connective tissues. We observe that these DOPA residues endow collagen with substantial radical scavenging capacity. When reducing radicals, DOPA residues work as redox relay: they convert to the quinone and generate hydrogen peroxide. In this dual function, DOPA outcompetes its amino acid precursors and ascorbic acid. Our results establish DOPA residues as redox-active side chains of collagens, probably protecting connective tissues against radicals formed under mechanical stress and/or inflammation.
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http://dx.doi.org/10.1002/anie.202216610 | DOI Listing |
Int J Biol Macromol
January 2025
Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia.
The search for new hemostatic materials remains a priority for researchers, as the problem of uncontrolled hemorrhage during surgical interventions or traumatic injuries represents a significant challenge. The objective of the study was to identify novel polysaccharide structures with enhanced hemostatic properties based on chitosan. The number of chitosan derivatives with two substituents was synthesized and characterized by H NMR, FTIR.
View Article and Find Full Text PDFAntioxidants (Basel)
November 2024
Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
is a low-molecular weight, non-aromatic reagent, widely used in industry, such as in the manufacture of paper, textiles, plastics, cosmetics, and dyes. ACR is formed during the cooking of starchy food and its toxicity results mainly by conferring oxidative stress by elevating reactive oxygen species (ROS). To identify potential antidotes for ACR toxicity, we evaluated the efficacy of several thiol-based molecules known for ROS-scavenging, disulfide-reducing properties, and inhibition of oxidative stress-induced activation of the mitogen-activated protein kinases (MAPKs): the extracellular-signal-regulated-kinases (ERK1/2), p38-mitogen-activated-protein-kinases (p38), and c-Jun-N-terminal-kinases (JNKs).
View Article and Find Full Text PDFiScience
December 2024
Biology of Marine Organisms and Biomimetics Unit, Research Institute for Biosciences, University of Mons, Place du Parc 23, 7000 Mons, Belgium.
Mussels and tubeworms have evolved similar adhesive systems to cope with the hydrodynamics of intertidal environments. Both secrete adhesive proteins rich in DOPA, a post-translationally modified amino acid playing essential roles in their permanent adhesion. DOPA is produced by the hydroxylation of tyrosine residues by tyrosinase enzymes, which can also oxidize it further into dopaquinone.
View Article and Find Full Text PDFJ Agric Food Chem
December 2024
Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, Fujian 350117, China.
PLoS One
November 2024
Department of Biochemistry, Hazara University, Mansehra, Khyber Pakhtunkhwa, Pakistan.
Tyrosinase, a copper-containing oxidase, plays a vital role in the melanin biosynthesis pathway. Mutations in the tyrosinase gene can disrupt the hydroxylation of tyrosine, leading to decreased production of 3,4-dihydroxyphenylalanine (DOPA). Consequently, this impairs the subsequent formation of dopaquinone, a key precursor in melanin pigment synthesis.
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