Visualization of human plasma fibrinogen adsorbed on highly oriented pyrolytic graphite by scanning probe microscopy

Formation and Topotactical Orientation of Fibrinogen Nanofibrils on Graphite Nanostructures

“…The clusters and network formation have also been found by others previously. [10,16,18] The mechanism of the nanofibril formation observed in this study is not obvious, particularly in the absence of thrombin and Ca 2þ ions. To the knowledge of the authors it has not been reported in literature so far, that fg is able to polymerize and build fibrin in the absence of thrombin and Ca 2þ at the buffer conditions used in the present study.…”

“…[1,29] Under physiological conditions in the body a fibrin network is formed in the presence of Ca 2þ and thrombin. [18,[41][42][43] Thrombin is a serine protease that catalyzes the cleavage of the fibrinopeptides A and B in the central E region of the fg molecule [25] (for schematic representation of the fg molecule see Fig. 3a).…”

“…Atomic force microscopy (AFM) achieves molecular resolution of adsorbed molecules and gives direct insights into protein conformation, assembly and response to surface topography. Therefore, AFM has been widely used to investigate protein adsorption, including protein adsorption on self-assembled monolayers (SAMs), [11][12][13][14] patterned surfaces, [15] mica, [16,17] highly oriented pyrolytic graphite (HOPG), [16,18] glass, [19] silicon, [20] silicon dioxide, [21] titanium, [10,22] and polymer surfaces. [23] Many previous studies investigated the influence of concentration, pH and surface topography on the conformation of adsorbed single fg molecules with high resolution microscopy methods or investigated the induced fg polymerization and fibrin formation on the surface by adding thrombin and calcium ions.…”

Evaluation of fibrinogen self‐assembly: role of its αC region

“…Reports on ordered aggregation of fibrinogen induced by hydrophobic adsorption demonstrated networks that appeared surface bound [21–24], and did not form by des‐αC fibrinogen [21]. In the present study we characterized this process further and tested the role of the αC‐domains.…”

Sum Frequency Generation Studies on Bioadhesion: Elucidating the Molecular Structure of Proteins at Interfaces

“…With AFM, different model surfaces have been examined: mica, [77–84] graphite, [77, 78, 82, 84] silicon, [85–87] silicon dioxide, [18, 88] titanium oxide, [89] titanium, [90] stainless steel, [75, 91] carbon thin films, [92] surface-assembled monolayers, [84, 93–95] and different types of polymers. [80, 96–99] Other techniques used over the years have included: scanning probe microscopy, [95, 100] radioisotope labeling, [101–103] X-ray photoelectron spectroscopy, [90] ellipsometry, [92, 104] polarization-modulation infrared reflection-absorption spectroscopy, [75] immunogold staining for imaging, [105] field emission scanning electron microscopy, [106] ELISA,[107] etc. Even mass spectrometry has recently become involved in studying fibrinogen conformations at interfaces.…”