title: Crowding versus molecular seeding: NMR studies of protein aggregation in hen egg white.
abstract: In living systems, proteins are surrounded by many other macromolecules of different nature, at high total concentrations. In the last few years, there has been an increasing effort to study biological macromolecules directly in natural crowded environments, such as in intact bacterial cells or by mimicking natural crowding by adding proteins, polysaccharides or even synthetic polymers. We have recently proposed hen egg white (HEW) as a suitable, natural medium to study macromolecules in crowding conditions. Here, we show that HEW can increase dramatically the aggregation kinetics of proteins with an in-built tendency to associate. By dissecting the mechanism we demonstrate that only part of this effect is due to crowding, while another factor playing an important role is the interaction with proteins from the milieu. High molecular weight glycoproteins present in HEW act as efficient molecular seeds for aggregation. Our results bear important consequences for in-cell NMR studies and suggest a role of glycosylated proteins in aggregation.
authors.affiliation: National Institute for Medical Research, The Ridgeway, London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Sanfelice
authors.forename: M
authors.initials: M
authors.lastname: Adrover
authors.forename: G
authors.initials: G
authors.lastname: Martorell
authors.forename: A
authors.initials: A
authors.lastname: Pastore
authors.forename: P A
authors.initials: PA
authors.lastname: Temussi
mesh_terms: D000818:Animals; D002645:Chickens; D004527:Egg Proteins / Q000737:chemistry* / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
chemical_list: D004527:Egg Proteins; D006023:Glycoproteins; D009419:Nerve Tissue Proteins