title: Growth and shape stability of a biological membrane adhesion complex in the diffusion-mediated regime.
abstract: We examine the process of expansion of a focal adhesion complex by which a biological membrane containing mobile binders adheres to a substrate with complementary binders. Attention is focused on the situation, common among living cells, in which the mean mobile binder density is insufficient to overcome generic resistance to close approach of the membrane to its substrate. For the membrane to adhere, binders must be recruited from adjacent regions to join an adhesion patch of density adequate for adhesion, thereby expanding the size of the patch. The specific configuration examined is the expansion of a circular adhesion zone for which diffusive binder transport driven by a chemical potential gradient is the mechanism of binder recruitment. An aspect of the process of particular interest is the stability of the circular shape of the expanding front. It is found that the adhesion front radius increases as radical(t), where t is the time elapsed since nucleation, and that the circular shape becomes unstable under sinusoidal perturbations for radii large compared with the nucleation size, as observed in recent experiments.
authors.affiliation: Division of Engineering, Brown University, Providence, RI 02912, USA. shenoyv@engin.brown.edu
authors.forename: V B
authors.initials: VB
authors.lastname: Shenoy
authors.forename: L B
authors.initials: LB
authors.lastname: Freund
mesh_terms: D002448:Cell Adhesion; D002462:Cell Membrane
references.citation: Science. 1999 Nov 5;286(5442):1172-4
references.pmid: 10550057
references.citation: Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Apr;61(4 Pt B):4253-67
references.pmid: 11088221
references.citation: Biophys J. 2001 Nov;81(5):2743-51
references.pmid: 11606287
references.citation: Q Rev Biophys. 2001 May;34(2):105-267
references.pmid: 11771120
references.citation: Proc Natl Acad Sci U S A. 2002 Jun 11;99(12):7854-9
references.pmid: 12048237
references.citation: Proc Natl Acad Sci U S A. 2003 Feb 18;100(4):1484-9
references.pmid: 12552122
references.citation: J Cell Biol. 1996 Feb;132(3):465-74
references.pmid: 8636222
references.citation: Chemphyschem. 2004 Mar 19;5(3):383-8
references.pmid: 15067875
references.citation: Phys Rev Lett. 2004 Sep 3;93(10):108102
references.pmid: 15447454
references.citation: Science. 1978 May 12;200(4342):618-27
references.pmid: 347575
references.citation: Biophys J. 1984 Jun;45(6):1051-64
references.pmid: 6743742
references.citation: Proc R Soc Lond B Biol Sci. 1988 Jun 22;234(1274):55-83
references.pmid: 2901109
references.citation: Biomaterials. 1990 Jan;11(1):24-31
references.pmid: 2302446
references.citation: Eur Biophys J. 2003 Jul;32(4):342-54
references.pmid: 12851792