Lipocalins ( English lipocalins ) is a group of transport proteins with a characteristic secondary structure. They contain eight antiparallel beta-folded peptide sequences that form a cylinder . Such a “cylinder” contains a ligand- binding site inside.
Content
Distribution and features
Lipocalins are found in gram-negative bacteria , cells of vertebrates, invertebrates, as well as in plant cells. The main function of lipocalins is the transport of small hydrophobic molecules such as vitamin A , pheromones , prostaglandins , etc. Lipocalins play a role in the immune response , pheromone transport, prostaglandin synthesis in the cell, retinoid binding ( retinol-binding protein ) and some other processes.
Structure
Despite the fact that lipocalins are a group of proteins of a wide spectrum, they have a unique characteristic structure. The secondary and tertiary structure of lipocalins is characterized by the presence of eight sections connected to each other in an antiparallel beta-folded structure, which is folded into a symmetrical cylindrical “barrel-shaped” domain. Inside such a “barrel” is a ligand binding site, usually of a hydrophobic low molecular weight and biologically active component. Due to the rigidity of the structure, lipocalins can be relatively easily crystallized.
See also
- Apolipoprotein D
- Apolipoprotein M
Links
- The Lipocalins: A Review. The Edward Jenner Institute for Vaccine Research.
- Virtanen, Tuomas et al. "Important Animal Allergens Are Lipocalin Proteins: Why Are They Allergenic?" Department of Clinical Microbiology; University of Kuopio. International Archives of Allergy and Immunology, 1999.
- Bratt, T. "Lipocalins and Cancer". M&E Biotech. PubMed 10/18/2000.
- Charron, Jean-Benoit Frenette et al. "Identification, Expression, and Evolutionary Analyses of Plant Lipocalins" Département des Sciences Biologiques, Université du Québec à Montréal. 04/10/2005.
- Novotny, MV et al. "Pheromones, binding proteins and receptor responses in rodents" Institute for Pheromone Research, University of Indiana, Bloomington. Biochemical Society Transactions, 2003.
- Diwan, J. "Review: Protein Structure". Rensselaer Polytechnic Institute. 2003.