title: Progressive pearl necklace collapse mechanism for cerato-ulmin aggregation film.
abstract: Cerato-ulmin (CU) is a fungal toxin class II hydrophobin, involved in Dutch elm disease. The formation of hydrophobin films at the air-water interface is a key mechanism which plays a role of paramount importance at different stages of the fungal development. We present a study on the precursor stages of growth towards the self-assembly aggregation film of CU. Atomic force microscopy images of CU dropped on mica substrates indicate that the system self-organizes in almost one-dimensional pearl-necklace-like chains, which subsequently collapse and possibly merge to form extended and rather compact planar films. We propose and verify a simple model to describe the self-aggregation mechanism in terms of progressive thickening of the pearl chains due to the successive merging and collapse of the elementary constitutive units.
authors.affiliation: CSDC, Dipartimento di Fisica, Università degli Studi di Firenze, Via Sansone 1, Sesto Fiorentino, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Sbrana
authors.forename: D
authors.initials: D
authors.lastname: Fanelli
authors.forename: M
authors.initials: M
authors.lastname: Vassalli
authors.forename: L
authors.initials: L
authors.lastname: Carresi
authors.forename: A
authors.initials: A
authors.lastname: Scala
authors.forename: L
authors.initials: L
authors.lastname: Pazzagli
authors.forename: G
authors.initials: G
authors.lastname: Cappugi
authors.forename: Bruno
authors.initials: B
authors.lastname: Tiribilli
mesh_terms: D000388:Air / Q000032:analysis; D000818:Animals; D005656:Fungal Proteins / Q000378:metabolism*; D018625:Microscopy, Atomic Force / Q000379:methods; D009183:Mycotoxins / Q000378:metabolism*; D055156:Ophiostoma / Q000737:chemistry*; D049911:Pinctada / Q000737:chemistry; D010935:Plant Diseases / Q000382:microbiology; D011485:Protein Binding; D013499:Surface Properties; D034403:Ulmus / Q000382:microbiology; D014867:Water / Q000737:chemistry*
chemical_list: D005656:Fungal Proteins; D009183:Mycotoxins; D014867:Water; C079060:CU protein, Ophiostoma ulmi