Protein-surface interactions immobilization

Both the nature of protein-surface interactions and inherent properties of a specific enzyme will contribute to the catalytic activity of an immobilized biocatalyst. Adsorption of an enzyme onto a surface can induce conformational changes which affect the rate and specificity of the catalyst. The total amount of enzyme loading, enzyme distribution within the immobilization support, and microenvironment surroimding the supported enzyme can all influence enzyme-catalyst activity, specificity and stability. ... 

New developments in immobilization surfaces have lead to the use of SPR biosensors to monitor protein interactions with lipid surfaces and membrane-associated proteins. Commercially available (BIACORE) hydrophobic and lipophilic sensor surfaces have been designed to create stable membrane surfaces. It has been shown that the hydrophobic sensor surface can be used to form a lipid monolayer (Evans and MacKenzie, 1999). This monolayer surface can be used to monitor protein-lipid interactions. For example, a biosensor was used to examine binding of Src homology 2 domain to phosphoinositides within phospholipid bilayers (Surdo et al., 1999). In addition, a lipophilic sensor surface can be used to capture liposomes and form a lipid bilayer resembling a biological membrane. 

Some arrays used in proteomics contain antibodies covalently bound onto the array surface for immobilization. Then these antibodies capture corresponding antigens from a complex mixture. Afterwards, a series of analysis are carried out. For instance, bound receptors can reveal ligands. With this information in hand, binding domains for protein-protein interactions can be detected. The main problem in using microarray methods for proteomics is that protein molecules must show folding with the array in the correct conformation during the preparation and incubation. Otherwise, protein-protein interactions do not take place. 

To summarize, the model used in this paper captures many important features of protein structure and dynamics and is indeed seen to reproduce many of the general trends observed in SM-FRET experiments. At the same time, we have also observed several intriguing discrepancies between the model predictions and the experimental results. One possibility is that these discrepancies originate from shortcomings of the model. For example, the SM-FRET measurements reported in Refs. [30, 33] were performed on a coiled-coil that was immobilized on a positively charged amino-silanized glass surface and involved charged dye molecules. This implies that the protein-surface and donor-acceptor interactions may be dominated by electrostatic forces. Our... 

With the increasing interest in and application of DNA and protein microarrays, biosensors, cell surface interactions, and biomedical implants, various systems and strategies for the immobilization and patterning of biomolecules have been developed and some have become well established. A wide diversity of chemical methods for biomolecule immobilization on inorganic substrates has been implemented by different research groups. Often, the choice of the method is a compromise between effectiveness, cost, and technology. In consideration of stability and durability of the attached biomolecules, certainly, the covalent attachment has to be preferred. 

Hence, the overall resistance to the mass transfer predicted by this variant of the BAMcomb model is the sum of the resistance in the liquid film and the resistance in the pore fluid. The value of the liquid film mass transfer coefficient Kf can be calculated from literature correlations,400,407,408 while the method for the estimation of the apparent pore liquid mass transfer coefficient Kp can be derived from Eq. (163). The surface interaction between the protein and the immobilized ligand at the internal particle surface can be treated in the same way as for nonporous particles, i.e.,... 

The distinction between substrate binding and supersubstrate binding as it has developed from studies on lipolytic enzymes has far-reaching implications. Many of the substrates of interacellular metabolism are partially immobilized, i.e., they are parts of biological membranes. The enzymes acting on such substrates are much larger than the substrate molecules, and the reactive center of the enzyme occupies only a small part of the surface of the enzymic protein. The rest of the protein must interact with the environment and in particular with the matrix in which... 

---