Structural studies of the neural-cell-adhesion molecule by X-ray and neutron reflectivity

Colin P. Johnson, Giovanna Fragneto, Oleg Konovalov, Virginie Dubosclard, Jean Francois Legrand, Deborah E. Leckband

Research output: Contribution to journalArticlepeer-review

Abstract

The structures of adhesion proteins play an important role in the formation of intercellular junctions and the control of intermembrane spacing. This paper describes the combination of neutron and X-ray specular reflectivity measurements to investigate the structure of the ectodomain of the neural-cell-adhesion molecule (NCAM). The measurements with unmodified NCAM suggest the presence of a bend in the extraceullar region. Measurements with the polysialic-acid-modified form of NCAM reveal that, at physiological ionic strength, the carbohydrate chains extend beyond the range of the unmodified protein. The excluded volume of the polymer is also ionic-strength-dependent, as expected for a polyelectrolyte. The structural characteristics obtained from these independent analyses of X-ray and neutron reflectivity data agree with each other, with prior reflectivity studies, and with molecular dimensions obtained from direct-force measurements. These results provide structural insights into the configuration of the NCAM ectodomain and the regulation of NCAM adhesion by post-translational modification.

Original languageEnglish (US)
Pages (from-to)546-554
Number of pages9
JournalBiochemistry
Volume44
Issue number2
DOIs
StatePublished - Jan 18 2005

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Structural studies of the neural-cell-adhesion molecule by X-ray and neutron reflectivity'. Together they form a unique fingerprint.

Cite this