Biospecific interactions

The important advantage of the immunosorbents based on WPG-PA is the fast rate of biospecific interaction between the oligosaccharides and antibodies. For B-trisaccharide-WPG-PA the average sorption time of monoclonal B8 antibodies was 20 times shorter than with B-trisaccharide-Sepharose 4B. The role of the flexible polymeric spacer, therefore, is in this case very pronounced. 

Jonsson, U., Fagerstam, L., Ivarsson, B., Johnsson, B., Karlsson, R., Lundh, K., Lofas, S., Persson, B., Roos, H., Ronnberg, I., Sjolander, S., Stenberg, E., Stahlberg, R., Urbaniczky, S., Ostlin, H., and Malmqvist, M. (1991). Real-time biospecific interaction analysis using surface plasmon resonance and a sensor chip technology. Biotechniques 11, 620-627. 

Lundstrom I., Real-time biospecific interaction analysis, Biosens. Bioelectron. 1994 9 725-736. 

Differences in protein surface charge at a given pH Differences in mass/shape of different proteins Based upon biospecific interaction between a protein and an appropriate ligand... 

M. Minunni and M. Mascini, "Detection of Pesticide in Drinking Water Using Real-Time Biospecific Interaction Analysis (BIA)," Analytical Letters 26, 1441-1460 (1993). 

P Lundahl, A Lundqvist, E Greijer, eds. Quantitative Analysis of Biospecific Interactions. Amsterdam Harwood Academic, 1998. 

A Lundqvist, E Brekkan, L Haneskog, Q Yang, J Miyake, P Lundahl. Determination of transmembrane protein affinities for solutes by frontal chromatography. In P Lundahl, A Lundqvist, E Greijer, eds. Quantitative Analysis of Biospecific Interactions. Amsterdam Harwood Academic, 1998, pp 79-93. 

More recently, increasing research attention has focused upon the use of mucoadhesive delivery systems in which the biopharmaceutical is formulated with/encapsulated in molecules which interact with the intestinal mucosa membranes. The strategy is obviously to retain the drug at the absorbing surface for a prolonged period. Non-specific (charge-based) interactions can be achieved by the use of polyacrylic acid, while more biospecific interactions are achieved by using selected lectins or bacterial adhesion proteins. Despite intensive efforts, however, the successful delivery of biopharmaceuticals via the oral route remains some way off. 

Competitive desorption (elution) has the advantage of very smooth conditions for protein structure, but the disadvantage of difficult removing of the ligand when further biospecific interactions are intended. 

Starodub NF, Dibrova TI, Shirshov YuM, Kostiukevich KV (1997) Development of sensor based on the surface plasmon resonance for control of biospecific interaction. In Proceedings of eurosensors 12 and 11th european conference on solid-state transducers, Warsaw, Poland, 3 1429-1432,21-24 Sept... 

Johne, B., Gadnell, M., and Hansen, K (1993) Epitope mapping and binding kinetics of monoclonal antibodies studied by real time Biospecific Interaction Analysis using surface plasmon resonance J Immunol Methods 160, 191—198... 

Oligonucleotide probes may be labeled with small fluorescent molecules for detection of hybridization by luminescence. Fluorescent probes are widely used in assay systems involving biospecific interactions. Receptors for ligands may be localized in tissues or... 

Minunni, M. and M. Mascini (1993). Detection of pesticide in drinking water using real-time biospecific interaction analysis (BIA). Anal. Lett., 26 1441-1460. 

Gambari R. Biospecific interaction analysis a tool for drug discovery and development. Am J Pharmacogenomics 2001 1 119-135. 

Partial pressure (10-1000 psi) Activity, effective partial pressure Activity, concentration Ion concentration, voltage Electrochemical interactions Biospecific interactions... 

The acronyms are RPC, reversed phase chromatography EIC, ion-exchange chromatography HIC, hydrophobic interaction chromatography BIC, biospecific interaction (affinity) chromatography. 

Capillary affinity electrophoresis (CAE) or affinity capillary electrophoresis (ACE) — An electrophoretic separation technique (- electrophoresis), in which -> analytes are separated in a capillary, with the -> supporting (background) electrolyte containing substances capable of specific, often biospecific, interactions with the analytes. Ref [i] Riekkola ML, Jonsson jA, Smith RM (2004) Pure Appl Chem 76 443... 

At low HSA concentrations the model fits well the whole breakthrough curve (Fig. 5). Two parameters are necessary to describe the model, the column capacity Qx and the number of transfer units n. The overall adsorption process is described by an apparent association rate constant that includes the transport to the active sites and the biospecific interaction (Eq. (6)]. 

Table 2 lists the two parameters n and Qx necessary to describe the model as determined with columns differing by the density of immobilized polyclonal antibody. As previously described, from the variation of the column capacity one can evaluate the contribution to the transport to the binding sites (I/nmt = 0.040) and calculate the effective adsorption rate constant ka. The results agree with those obtained from frontal analysis. The value of the apparent adsorption rate constant k is close to the value of Aa for experiments carried out both at high flow rates and with an immunoadsorbent column of low capacity 22). In this case, the rate-controlling step is the biospecific interaction. 

Malmqvist M (1993) Biospecific interaction analysis using biosensor technology. Nature 361 186-187... 

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