Glycopolymer charge density determines conformation in human ocular mucin gene products: an atomic force microscope study

Andrew N. Round, Monica Berry, Terry J. McMaster, Anthony P. Corfield, Mervyn J. Miles

    Research output: Contribution to journalArticlepeer-review

    42 Citations (Scopus)

    Abstract

    Atomic force microscopy (AFM) has been applied to the study of heterogeneity in the structure and function of individual biopolymers with complex structures such as glycoproteins, polysaccharides and nucleic acids. In this work we describe experiments which shed light on the heterogeneity of human ocular mucin gene products. By separating samples of native human ocular mucins on a caesium chloride density gradient, at least three populations consisting predominantly of products of the gene MUC5AC can be identified. Separation on the caesium chloride density gradient is governed by molecular architecture and charge density, and thus provides a route to the discrimination between different glycoforms within a glycoprotein sample. AFM images of these populations show that each is characterised by different conformational properties and polymer diameters, both of which can be attributed to differences in the degree and nature of glycosylation. These differences in glycosylation are likely to be the result of post-translational processing and may also have functional consequences. The AFM's ability to examine the composition of a predominantly single gene product population at the level of the single molecule allows the consequences of post-translational process heterogeneity to be examined at high resolution. (C) 2003 Elsevier Inc. All rights reserved.
    Original languageEnglish
    Pages (from-to)246-253
    Number of pages8
    JournalJournal of Structural Biology
    Volume145
    Issue number3
    DOIs
    Publication statusPublished - 2004

    Cite this