The majority of eukaryotic secretory and membrane proteins contain disulfide bonds, which are strongly conserved within protein families because of their crucial role in folding or function. The exact role of these disulfide bonds during folding is unclear. Using virus-driven evolution we generated a viral glycoprotein variant, which is functional despite the lack of an absolutely conserved disulfide bond that links two antiparallel beta-strands in a six-stranded beta-barrel. Molecular dynamics simulations revealed that improved hydrogen bonding and side chain packing led to stabilization of the beta-barrel fold, implying that beta-sheet preference codirects glycoprotein folding in vivo. Our results show that the interactions between two beta-strands that are important for the formation and/or integrity of the beta-barrel can be supported by either a disulfide bond or beta-sheet favoring residues.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2575144 | PMC |
http://dx.doi.org/10.1091/mbc.e08-07-0670 | DOI Listing |
Protein Sci
February 2025
Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia.
The chemokine XC motif chemokine ligand 1 (XCL1) is an unusually specialized member of a conserved family of around 50 small, secreted proteins that are best known for their ability to stimulate the directional migration of cells. All chemokines adopt a very similar folded structure that binds a specific G protein-coupled receptor (GPCR), and most chemokines bind extracellular matrix glycosaminoglycans, often in a dimeric or oligomeric form. Owing in part to the lack of a disulfide bond that is conserved in all other chemokines, XCL1 interconverts between two distinct structures with distinct functions.
View Article and Find Full Text PDFChem Asian J
January 2025
Indian Institute of Science, Inorganic and Physical Chemistry, Indian Institute of Science, 560 012, Bangalore, INDIA.
Intracellular delivery of proteins is an important barrier in the development of strategies to deliver functional proteins and protein therapeutics into the cells to realize their full potential in biotechnology, biomedicine, cell-based therapies, and gene editing protein systems. Most of the intracellular protein delivery strategies involve the conjugation of cell penetrating peptides to enable and enhance the permeability of plasma membrane of mammalian cells to allow proteins to enter cytosol. Small molecules conjugations such as (p-methylphenyl) glycine, pyrenebutyrate and cysteines are used for the same purpose.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey.
Cysteine derivatives having disulfide bonds in their side chains can be used as redox-responsive organogelators. The disulfide bond can be cleaved in the presence of certain reducing agents like thiol derivatives such as glutathione (GSH), which is a tripeptide that consists of cysteine, glutamic acid, and glycine. Studies show that cells of certain cancers have higher levels of glutathione due to increased production of reactive oxygen species (ROS).
View Article and Find Full Text PDFJ Sci Food Agric
January 2025
College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan, China.
Background: The quality of Acipenser sinensis deteriorates significantly during frozen storage due to its high water, protein, and unsaturated fatty acid content. Conventional freezing methods are insufficient to preserve it effectively. This study investigated the effects of liquid nitrogen freezing (LNF) on the quality and myofibrillar protein (MP) characteristics of A.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2025
San Francisco State University, Department of Chemistry and Biochemistry, San Francisco, CA, USA; Pacific Northwest National Laboratory, Earth and Biological Sciences Division, Richland, WA, USA. Electronic address:
Polyamines within the cell are tightly regulated by spermidine/spermine N-acetyltransferase (SSAT) enzymes. While several SSATs have been investigated in different bacterial species, there is still a significant gap in knowledge about which proteins are functional SSATs in many organisms. For example, while it is known that Pseudomonas aeruginosa synthesizes the polyamine spermidine, the SSAT that acetylates this molecule and its importance in regulating intracellular polyamines remains unknown.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!