Glycosaminoglycans in extracellular matrix organisation: are concepts from soft matter physics key to understanding the formation of perineuronal nets?. (June 2018)

• Record Type: Journal Article
• Authors: Richter, Ralf P; Baranova, Natalia S; Day, Anthony J; Kwok, Jessica CF
• Is Part Of: Current opinion in structural biology. Volume 50(2018)
• Page Start: 65
• Page End: 74
• Publication Date: 2018-06
• Subjects: Molecular biology -- Periodicals; 570
• DOI: 10.1016/j.sbi.2017.12.002
• Languages: English
• ISSNs: 0959-440X

Abstract

Highlights: Glycosaminoglycan physical properties contribute to distinct biochemical functions. Hyaluronan is a unique scaffolding material, enabling matrix self-organisation. GAG-binding proteins organise GAG matrices. A balance of repulsion and cross-linking defines GAG matrix organisation. Soft matter physics principles underpin the formation of holes in perineuronal nets. Abstract : Conventional wisdom has it that proteins fold and assemble into definite structures, and that this defines their function. Glycosaminoglycans (GAGs) are different. In most cases the structures they form have a low degree of order, even when interacting with proteins. Here, we discuss how physical features common to all GAGs — hydrophilicity, charge, linearity and semi-flexibility — underpin the overall properties of GAG-rich matrices. By integrating soft matter physics concepts (e.g. polymer brushes and phase separation) with our molecular understanding of GAG–protein interactions, we can better comprehend how GAG-rich matrices assemble, what their properties are, and how they function. Taking perineuronal nets (PNNs) — a GAG-rich matrix enveloping neurons — as a relevant example, we propose that microphase separation determines the holey PNN anatomy that is pivotal to PNN functions.