Cell-Binding Arrays

For the cell-binding arrays, 300-pm spots are preferred 100-pm spots can be used for enzyme-linked colorimetric and other assays. 

Lectin arrays Lectin binding pmol-nmol Structural motifs Structural analysis in tissue context, living cells can be screened, no fractionation required Limited by availability and specificity of characterized lectins, quantification is challengi ng... 

Proteins that cross-link actin filaments bind to their sides to produce bundles or three-dimensional networks (Otto, 1994). In microvilli, approximately 20 actin filaments of the core are cross-linked by villin (95 kD) and fimbrin (68 kD) in helical array to form a compact bundle (Figure 5). Filamin (2 x 250 kD) induces the formation of an actin network with gel formation. By immunofluorescence microscopy, this ABP is found in the ruffled, motile edge of cultured cells, where only actin filaments are abundant. 

The ultimate goal of microarray-based expression analysis is to acquire a comprehension of the entire cellular process, in order to exploit and to standardize the multidi-menisional relations between genotype and phenotype. However, an increasingly important parameter, which has not yet been substantially taken into account, is the role of cellular translation. This means that mRNA expression data need to be correlated with the assortment of proteins actually present in the cell. One approach is based on the use of microarrays containing double-stranded DNA probes for the analysis of DNA-protein interaction and, thus, the detection and identification of DNA-binding proteins by means of fluorescence [130] or mass spectrometry analysis [131]. Moreover, substantial efforts are currently under way to develop protein, antibody, or even cell arrays, applicable to the cor-... 

Figure 3.3 Molecular structure of G-protein-coupled receptors. In (a) the electron density map of bovine rhodopsin is shown as obtained by cryoelectron microscopy of two-dimensional arrays of receptors embedded in lipid membrane. The electron densities show seven peaks reflecting the seven a-helices which are predicted to cross the cell membrane. In (b) is shown a helical-wheel diagram of the receptor orientated according to the electron density map shown in (a). The diagram is seen as the receptor would be viewed from outside the cell membrane. The agonist binding pocket is illustrated by the hatched region between TM3, TM5 and TM6. (From Schertler et al. 1993 and Baldwin 1993, reproduced from Schwartz 1996). Reprinted with permission from Textbook of Receptor Pharmacology. Eds Foreman, JC and Johansen, T. Copyright CRC Press, Boca Raton, Florida...

The most frequent application of SPOT-synthesis has been in the preparation of peptide arrays for the identification of linear B-cell epitopes. If the protein antigen is known, a set of overlapping peptides that encompass the entire sequence can be readily synthesized and assayed for binding of antibody (Reineke et al., 1999). The individual residues critical for binding can then be determined by SPOT-synthesis of peptides containing amino acid substitutions. 

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