Atomic Resolution Structure of the HFBII Hydrophobin, a Self-assembling Amphiphile

Hakanpää, Johanna; Paananen, Arja; Askolin, Sanna; Nakari-Setälä, Tiina; Parkkinen, Tarja; Penttilä, Merja; Linder, Markus B.; Rouvinen, Juha

doi:10.1074/jbc.m309650200

Cited by 215 publications

(220 citation statements)

References 30 publications

Supporting

Mentioning

206

Contrasting

Unclassified

Order By: Relevance

“…HFBII features fi ve positively charged amino acids on the exposed hydrophilic side, [ 21,36,37 ] and its isoelectric point (pI) was measured to be 5.8 (see Figure S1 and Table S1 of the Supporting Information). Therefore, the hypothesized interaction between HFBII and F10 was expected to be electrostatic and pH dependent.…”

Section: Resultsmentioning

confidence: 99%

“…[ 3 ] However, this approach necessitates a rather fungi. [ 20 ] The presence of eight cysteine residues arranged in four internal disulfi de bridges [ 21 ] signifi cantly enhances the resistance of these proteins to both heat and organic solvents. Most importantly, a discrete portion of their exposed surface is composed of amino acids with hydrophobic sidechains; this hydrophobic patch endows hydrophobins with exceptional amphiphilic properties and drives their spontaneous and rapid self-assembly at hydrophobic/hydrophilic interfaces, such as air/water and oil/water boundaries, where they pack into ordered structures and form remarkably strong and elastic fi lms.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hydrophobin as a Nanolayer Primer That Enables the Fluorinated Coating of Poorly Reactive Polymer Surfaces

Gazzera

Corti

Pirrie

et al. 2015

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

thick fi lm to achieve signifi cant durability and, therefore, requires a relatively large amount of fl uoropolymer. Alternative approaches, such as chemical grafting of fl uoropolymers by radical methods through irradiation, [ 6−8 ] plasma, [ 9−12 ] or direct fl uorination with fl uorine gas, [ 1,2,13 ] require only moderate amounts of fl uorinated surface modifi ers but are much more aggressive and, in some cases, potentially hazardous.Other possibilities involve functionalization with fl uorinated molecules/ polymers consisting of specifi c chemical moieties that are able to bind either covalently or noncovalently to the polymer surface. [ 4,5,14,15 ] However, to achieve sufficiently stable bonding, this general strategy requires the presence of reactive hydrophilic sites, typically OH groups, which are not typically observed on the surfaces of apolar, hydrophobic polymers, such as polyolefi ns, and need to be introduced via oxidizing pretreatments that are usually either energy-intensive or not environmentally friendly. [ 16−19 ] Expanding on this strategy, we present an effi cient, rapid, and more environmentally friendly method to perform the fl uorocarbon coating of hydrophobic polymer surfaces. The method is based on the use of hydrophobins, i.e., amphiphilic surface-active proteins, as a nanosized primer layer that adheres to the hydrophobic polymer surface, making the surface hydrophilic and preparing it for the subsequent binding of a fl uoropolymer containing ionic moieties.Hydrophobins are a class of nontoxic, surface-active, and fi lm-forming proteins that are produced by fi lamentous A new and simple method is presented to fl uorinate the surfaces of poorly reactive hydrophobic polymers in a more environmentally friendly way using the protein hydrophobin (HFBII) as a nanosized primer layer. In particular, HFBII, via electrostatic interactions, enables the otherwise ineffi cient binding of a phosphate-terminated perfl uoropolyether onto polystyrene, polypropylene, and low-density polyethylene surfaces. The binding between HFBII and the perfl uoropolyether depends signifi cantly on the environmental pH, reaching the maximum stability at pH 4. Upon treatment, the polymeric surfaces mostly retain their hydrophobic character but also acquire remarkable oil repellency, which is not observed in the absence of the protein primer. The functionalization proceeds rapidly and spontaneously at room temperature in aqueous solutions without requiring energy-intensive procedures, such as plasma or irradiation treatments.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Hydrophobin as a Nanolayer Primer That Enables the Fluorinated Coating of Poorly Reactive Polymer Surfaces

Gazzera

Corti

Pirrie

et al. 2015

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

show abstract

“…Indeed, on one side of their molecular surface, some exposed hydrophobic aliphatic side chains form a flat hydrophobic patch, whilst polar or charged residues are confined to the other side [3] and [4]. The hydrophobic patch could be involved in interaction with an identical protein partner that obscures the hydrophobic region.…”

Section: Introductionmentioning

confidence: 99%

Marine fungi as source of new hydrophobins

Cicatiello

Gravagnuolo

Varese

et al. 2016

International Journal of Biological Macromolecules

View full text Add to dashboard Cite

Highlights23 Marine fungi have been analyzed to identify hydrophobin producers.6 New hydrophobins have been isolated. 4 Proteins belong to class I and 2 to class II hydrophobins.One of the new class I hydrophobins stably changes the wettability of a crystalline silicon chip. One of the new class II hydrophobin is endowed with remarkable emulsification capacity. AbstractHydrophobins have been described as the most powerful surface-active proteins known. They are produced by filamentous fungi and exhibit a distinct amphiphilic structure determining their selfassembly at hydrophilic-hydrophobic interfaces and surfactant properties which have been demonstrated to be useful for several biotechnological applications. The marine environment represents a vast natural resource of new molecules produced by organisms growing in various stressful conditions. This study was focused on the screening of 100 marine fungi from Mycoteca Universitatis Taurinensis (MUT) for the identification of new hydrophobins. Four different methods were set up to extract hydrophobins of class I and II, from the mycelium or the culture broth of fungi. Six fungi were selected as the best producers of hydrophobins endowed with different characteristics. Their ability to form stable amphiphilic films and their emulsification capacity in the presence of olive oil was evaluated. Figure options Graphical abstract

show abstract

“…According to X-ray crystallography the HFBII monomer is spherical (Hakanpä ä , Paananen, Askolin et al, 2004). Based on small-angle X-ray scattering results both HFBI and HFBII exist as tetramers in solution (Torkkeli et al, 2002) in concentrations of 10-100 mg ml À1 .…”

Section: Introductionmentioning

confidence: 99%

“…These arise from the amphiphilic structure of the proteins, where the hydrophobic and hydrophilic parts are separated (Hakanpä ä , Paananen, Askolin et al, 2004;Kwan et al, 2006). Hydrophobins lower the surface tension of water even down to one third (Wö sten et al, 1999;Askolin et al, 2006), adhere to various surfaces and self-assemble on hydrophobic/hydrophilic interfaces.…”

Section: Introductionmentioning

confidence: 99%

Self-assembled films of hydrophobin protein HFBIII from Trichoderma reesei

Kisko¹,

Szilvay²,

Vuorimaa³

et al. 2007

J Appl Crystallogr

Self Cite

View full text Add to dashboard Cite

Hydrophobins are a group of small amphiphilic proteins which are known to self-assemble on interfaces. They contain eight conserved cysteine residues, which make four disulfide bridges. A new hydrophobin protein, HFBIII, from the fungus Trichoderma reesei contains one extra cysteine residue, giving the protein a naturally reactive site. The self-assembly of hydrophobin protein HFBIII was studied using grazing-incidence X-ray diffraction and reflectivity. HFBIII self-assembles into a hexagonally ordered monolayer at an air/water interface and also forms crystalline coatings on a silicon substrate. The lattice constants for the hexagonal coatings are a = b = 56.5 Å , = 120 . The selfassembled structure in the HFBIII film is very similar to those formed by two other T. reesei hydrophobins, HFBI and HFBII.

show abstract

Atomic Resolution Structure of the HFBII Hydrophobin, a Self-assembling Amphiphile

Cited by 215 publications

References 30 publications

Hydrophobin as a Nanolayer Primer That Enables the Fluorinated Coating of Poorly Reactive Polymer Surfaces

Hydrophobin as a Nanolayer Primer That Enables the Fluorinated Coating of Poorly Reactive Polymer Surfaces

Marine fungi as source of new hydrophobins

Self-assembled films of hydrophobin protein HFBIII from Trichoderma reesei

Contact Info

Product

Resources

About