Calcium-Induced Conformational Transition of Trout Ependymins Monitored by Tryptophan Fluorescence
Bernhard Ganss1, 2, Werner Hoffmann*, 1, 3
Identifiers and Pagination:Year: 2009
First Page: 14
Last Page: 17
Publisher Id: TOBIOCJ-3-14
Article History:Received Date: 20/11/2008
Revision Received Date: 05/12/2008
Acceptance Date: 20/1/2009
Electronic publication date: 24/2/2009
Collection year: 2009
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Ependymins are secretory, calcium-binding sialoproteins which are the predominant constituents of the cerebrospinal fluid of many teleost fish. A bound form of these regeneration-responsive glycoproteins is associated with collagen fibrils of the extracellular matrix. Here, the tryptophan fluorescence of ependymins was monitored at various Ca2+ concentrations. Two distinct states were identified with a relatively sharp transition at about 1 mM Ca2+. In agreement with previous circular dichroism measurements, this strongly supports the hypothesis that a calcium-induced conformational change is important for the interaction of ependymins with components of the extracellular matrix. Such interactions with constituents of various basal laminae would also explain the important roles of piscine ependymins as well as invertebrate and mammalian ependymin-related proteins for cell adhesion processes and cell migration.