Chemistry-specific surface adsorption of the barnacle settlement-inducing protein complex

Gregarious settlement in barnacle larvae (cyprids) is induced by a contact pheromone, the settlement-inducing protein complex (SIPC). The SIPC has been identified both in the cuticle of adult barnacles and in the temporary adhesive secretion (footprint) of cyprids. Besides acting as a settlement inducer, the presence of the SIPC in footprints points to its additional involvement in the adhesion process. SIPC adsorption behaviour was therefore investigated on a series of self-assembled monolayers (SAMs) by surface plasmon resonance at the pH of seawater (8.3). Fibrinogen and α 2 -macroglobulin (A2M) (blood complement protease inhibitors with which the SIPC shares 29% sequence homology) were used in the adsorption experiments as positive and negative standards, respectively. The mass uptake of the SIPC was comparable to that of fibrinogen, with adsorption observed even on the protein-resistant oligo(ethylene glycol) surface. Notably, on the positively charged SAM the SIPC showed a kinetic overshoot, indicating a metastable configuration causing the amount of adsorbed protein to temporarily exceed its equilibrium value. A2M adsorption was low or negligible on all SAMs tested, except for the positively charged surface, indicating that A2M adsorption is mainly driven by electrostatics. Evaluation of SIPC non-specific adsorption kinetics revealed that it adsorbed irreversibly and non-cooperatively on all surfaces tested.

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Protein resistant oligo(ethylene glycol) terminated self-assembled monolayers of thiols on gold by vapor deposition in vacuum

Biointerphases ◽

10.1116/1.3407483 ◽

2010 ◽

Vol 5 (2) ◽

pp. 30-36 ◽

Cited By ~ 11

Author(s):

Laxman Kankate ◽

Udo Werner ◽

Andrey Turchanin ◽

Armin Gölzhäuser ◽

Helge Großmann ◽

...

Keyword(s):

Ethylene Glycol ◽

Vapor Deposition ◽

Self Assembled Monolayers ◽

Assembled Monolayers ◽

Self Assembled ◽

Protein Resistant

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Self-Assembled Monolayers as Models for Studying Protein Adsorption to Polymer Surfaces

MRS Proceedings ◽

10.1557/proc-237-311 ◽

1991 ◽

Vol 237 ◽

Cited By ~ 1

Author(s):

Kevin L. Prime ◽

George M. Whttesides

Keyword(s):

Ethylene Oxide ◽

Protein Adsorption ◽

Organic Materials ◽

Polymer Surfaces ◽

Self Assembled Monolayers ◽

Assembled Monolayers ◽

Poly Ethylene Oxide ◽

Self Assembled ◽

Protein Resistant ◽

Poly Ethylene

ABSTRACTSelf-assembled monolayers (SAMs) of functionalized alkanethiolates on gold are a well-characterized system for studying the interfacial properties of organic materials. We have used SAMs as models for the surfaces of organic polymers and used mem to study the adsorption of proteins onto organic materials. We have formed SAMs from mixtures of alkanethiols in which one alkanethiol is hydrophobic and the other is terminated by a short (2 ≤ n ≤ 17) oligomer of poly(ethylene oxide). These “mixed” SAMs effectively resist the adsorption of fibrinogen from moderately concentrated (1 mg/mL) solutions. Protein adsorption begins when < 5% of the accessible area of the surface consists of hydrophobic groups. These findings suggest that real protein-resistant monolayers must present an almost defect-free surface of oligo(ethylene oxide) groups in order to eliminate adsorption.

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