Jump to main content
Jump to site search

Issue 40, 2015
Previous Article Next Article

Spontaneous helical structure formation in laminin nanofibers

Author affiliations

Abstract

Laminin is a cross-shaped heterotrimer composed of three polypeptides chains that assembles into an insoluble extracellular matrix (ECM) network as part of the basement membrane, serving a vital role in many processes such as embryonic development, differentiation, and muscle and nerve regeneration. Here we engineered monodisperse laminin nanofibers using a surface-initiated assembly technique in order to investigate how changes in protein composition affect formation and structure of the network. Specifically, we compared laminin 111 with varying degrees of purity and with and without entactin to determine whether these changes alter biophysical properties. All the laminin types were reproducibly patterned as 200 μm long, 20 μm wide nanofibers that were successfuly released during surface-initiated assembly into solution. All nanofibers contracted upon release, and while initial lengths were identical, lengths of released fibers depended on the laminin type. Uniquely, the laminin 111 at high purity (>95%) and without entactin spontaneously formed helical nanofibers at greater than 90%. Atomic force microscopy revealed that the nanofiber contraction was associated with a change in nanostructure from fibrillar to nodular, suggestive of refolding of laminin molecules into a globular-like conformation. Further, for the high purity laminin that formed helices, the density of the laminin at the edges of the nanofiber was higher than in the middle, providing a possible origin for the differential pre-stress driving the helix formation. Together, these results show that variation in the purity of laminin 111 and presence of entactin can have significant impact on the biophysical properties of the assembled protein networks. This highlights the fact that our understanding of protein assembly and function is still incomplete and that cell-free, in vitro assays can provide unique insights into the ECM.

Graphical abstract: Spontaneous helical structure formation in laminin nanofibers

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 May 2015, accepted on 20 Aug 2015 and first published on 21 Aug 2015


Article type: Paper
DOI: 10.1039/C5TB01003A
Citation: J. Mater. Chem. B, 2015,3, 7993-8000
  •   Request permissions

    Spontaneous helical structure formation in laminin nanofibers

    J. M. Szymanski, M. Ba and A. W. Feinberg, J. Mater. Chem. B, 2015, 3, 7993
    DOI: 10.1039/C5TB01003A

Search articles by author

Spotlight

Advertisements