Assembling Fibrinogen at Air/Water and Solid/Liquid Interfaces Using Langmuir and Langmuir−Blodgett Films

Abstract

Langmuir films of pure fibrinogen (Fg) and Fg spread at the air/buffer interface and subphase containing electrolytes, NaCl, KCl, CaCl(2), and ZnCl(2), have been analyzed to understand the role of the surface/interface in mediating the organization of the protein eventually to fibrils. These films have been characterized by the surface pressure and surface potential-molecular area ((pi-A) and (DeltaV-A)) isotherms and Brewster angle microscopy (BAM). The Langmuir-Blodgett (LB) films of the protein transferred to the solid substrates have been characterized by scanning electron microscopy (SEM) and circular dichroism (CD). Our results suggest that fibrils are formed during organization at air/solution interface and also in LB films. The rate of formation of the fibril is the maximum for Fg with ZnCl(2). Adsorption of Fg to surfaces coated with a neutral lipid, dimyristoylphosphatidylcholine (DMPC), and a cationic lipid, dioctadecyldimethylammonium bromide (DOMA), from a range of solution concentrations has been studied using a quartz crystal microbalance (QCM). The work of adhesion of the protein on the solid surface shows fibril formation and positive adhesion for Fg in the presence of electrolytes. SEM results show that the adherent protein exhibits the widely reported nodulelike structure in the presence of CaCl(2) and ZnCl(2). These results provide definite evidence that specifically designed surfaces can promote adhesion of Fg and also activate fibril formation even in the absence of thrombin.

Controlling the Formation of Peptide Films: Fully Developed Helical Peptides are Required to Obtain a Homogenous Coating over a Large Area

“…Coating of inorganic substrates by densely‐packed and well‐organized organic layers has been easily achieved, typically with amphiphilic compounds, detergents, and lipids. More rarely, this technique has been applied to peptide compounds, despite potential applications of peptide films in biomedicine as templates for biomineralization, biocompatible coating of surfaces, scaffolds for tissue engineering, and in bionanotechnology as hybrid materials for optoelectronics, nanocatalysis, and biosensing …”

“…More rarely, this technique has been applied to peptide compounds, despite potential applications of peptide films in biomedicine as templates for biomineralization, biocompatible coating of surfaces, scaffolds for tissue engineering, and in bionanotechnology as hybrid materials for optoelectronics, nanocatalysis, and biosensing. [14][15][16][17][18][19] LB peptide films showed a rich morphology, like 'butterfly shapes', rectangles, dots, nanofibers or nanoribbons. Very recently, some of us characterized by molecular dynamics (MD) simulations the behaviour of TrGA at the air/water interface during a LB compression.…”

Intrinsic disorder of the bacterial cell division protein ZipA: coil‐to‐brush conformational transition

“…The use of physicochemical tools as a probe of conformational properties of adsorbed proteins at fluid interfaces is already longstanding (32). However, most of those studies deal with globular proteins (33)(34)(35)(36)(37). In the world of unstructured proteins, to the best of our knowledge, only the case of ␤-casein has been addressed (38 -41).…”

Influence of Ficoll on urea induced denaturation of fibrinogen

“…19,20 Studies have shown that designed surfaces can initiate fibril formation for Fg even in the absence of thrombin. 21 Fibrinogen being a plasma protein, is known for its role in blood clotting process. In the serum it is in high concentrations about 80 g/l.…”