Albumin molecules, adsorption onto

Fig. 54. a A typical image of closely packed pZT plasmid DNA molecules adsorbed onto a cationic lipid membrane of dipalmitoyldimethyl ammoniumylpropane. The image was recorded in 20 mMNaCl [513]. b Height image of tobacco mosaic viruses on the mica surface modified with bovine serum albumin (BSA). In contrast, direct adsorption from a solution containing BSA led to disperse adsorption of the TMV rods [517]... 

By adsorption onto an artificial sirrface, albumin molecules... 

The phenomenon of the rapid adsorption of albumin onto a PEUN surface may be associated with hydrophobic and hydrophilic interactions of the PEUN surface with some sequences of relatively hydrophobic amino acid residues in the interior of albumin. An albumin molecule is composed of three-subdomains (15). There are two gaps between the subdomains. One is a hydrophobic pocket with an affinity constant, K3=1.1x10 M for stearic acid the other is an intermediate hydrophobic pocket with K =1.5xl0 M for bilirubin (16). Perhaps the structure of adsorbed albumin in contact with a PEUN surface is composed of hydrophobic and hydrophilic regions corresponding or complementary to those of the PEUN surface, even though the exterior of native albumin is rich in hydrophilic amino acid side chains. 

XPS data on adsorbed proteins may also complement data obtained using radioassays owing to the fact that XPS only detects those proteins that are adsorbed at the external surface of a material, while radioassays also quantify molecules that would have diffused into the material. The adsorption and the penetration of lysozyme and albumin onto and into carboxymethylated PHEMA hydrogels were examined that way. The comparison of the amounts of protein detected by XPS and radiolabeling showed that lysozyme molecules mainly penetrate into the hydrogels, while a substantial fraction of albumin molecules remains located at the surface. " ... 

Yoshioka et al. [106] fixed the PNIPAAm so that an amine group was introduced at one end of the molecule—glutaldehyde onto an amine-based silica gel. They studied the adsorption and desorption of albumin... 

Bovine albumin has been studied to date via intrinsic TIRF only on hydrophilic quartz 92 159). The fluorescence maximum (1 mg/ml BSA in PBS) is 342 nm and shifts to 333 nm upon adsorption. These results suggest that the adsorption of BSA onto silica changes the conformation of the molecule such that the two Trp fluors are in a more hydrophobic environment. 

These values are close to the molecular sizes of the proteins, but much smaller than the surface micro-roughness (Figure 6.34) which occurs in the 0.1-0.5 jm range (Figures 6.34 and 6.36). The inequality d, principal axes of Fg molecule, respectively) is true on the Fg adsorption completion. A similar relation has been found for albumin adsorbed onto gold and Ti surfaces, but /tf>t(max,HSA 14 nm in the case of DLC and TiN. 

There are different methods to prevent the nonspecific adsorption of proteins onto surfaces, for example by adding surfactants or bovine serum albumin (BSA) to protein solutions, or by the widely applied method using self-assembled monolayers (SAMs) that are protein-resistant , such as SAMs with oUgo(ethylene glycol), l.e. OEG chains. These SAMs prevent nonspecific interactions due to their loose packing and the weU-hydrated nature. Such molecularly imprinted P-CD polymers, i.e. the P-CD molecular printboards were used as a platform for the immobilization of proteins through small multivalent orthogonal linker molecules. 

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