Affinity group specific

Affinity Group-specific liquid bonded to a solid surface Partition between surface liquid and mobile liquid... 

Herbicidal Inhibition of Enzymes. The Hst of known en2yme inhibitors contains five principal categories group-specific reagents substrate or ground-state analogues, ie, rapidly reversible inhibitors affinity and photo-affinity labels suicide substrate, or inhibitors and transition-state, or reaction-intermediate, analogues, ie, slowly reversible inhibitors (106). 

Figure 2.7. Identification ofphosphoproteins by site-specific chemical modification. A. Method of Zhou et al. (2001) involves trypsin digest of complex protein mixture followed by addition of sulfhydryl groups specifically to phosphopeptides. The sulfhydryl group allows capture of the peptide on a bead. Elution of the peptides restores the phosphate and the resulting phosphopeptide is analyzed by tandem mass spectrometry. B. Method of creates a biotin tag in place of the phosphate group. The biotin tag is used for subsequent affinity purification. The purified proteins are proteolyzed and identified by mass spectrometry.

Figure 7.22 Fluorescent dyes such as an amine-reactive Cy5 derivative can be coupled to amine-dendrimers at relatively high substitution levels to create intensely fluorescent detection agents. If the dendrimer also is deriva-tized to contain an affinity group or a targeting group then specific fluorescent detection at high sensitivity can be realized.

Grouping, in impact assessment, 24 821 Group-specific affinity ligands,... 

The availability of a great variety of group-specific adsorbents in prepacked columns makes possible the combination of FPLC and affinity chromatography for the separation and purification of proteins. 

The action of phosphatase on glucose-l-phosphate substrate is shown in Fig. 18. Phosphatase breaks the P-0 bond and releases the P04 group. In contrast phosphorylase which operates on the same substrate opens the C—0 bond. Apparently this affinity to specific bond sites, which in the present case amounts to a difference of ca. 1.5 A (Fig. 18) between the two bonds left and right from the oxygen, is... 

M Mosior, DA Six, EA Dennis. Group IV cytosolic phospholipase A2 binds with high affinity and specificity to phosphatidylinositol 4,5-bisphosphate resulting in dramatic increases in activity. JBiol Chem 273 2184-2191, 1998. 

Affinity separations include both group-specific and product-specific classes of interactions. Protein A has been extensively employed as a group-specific ligand to purify monoclonal antibodies, but its specificity is insufficient for some materials. For example, if a monoclonal is harvested in media containing 5% fetal bovine serum, the polyclonal bovine antibodies are not differentiated by a linear gradient on a protein A column but completely separated using step elution on a preparative cation exchanger column (ABx) [147],... 

A list of commercially available, group-specific affinity resins is shown in Table 5.5 [149]. The same suppliers also provide a variety of hydrophobic, reversed-phase, size-exclusion, and ion-exchange resins. 

Pseudo-biospecific ligands, such as metal chelates, amino acids, and dyes are simpler and less expensive molecules with a structural affinity to biomolecules (group specificity). Since they have simpler structures, they can be immobilized by stable, well defined chemical reactions to the chromatographic matrix. Their disadvantages are their lower specificity, as compared with biospecific ligands. However, there are many examples of molecules obtained from animal cell cultures that have been successfully purified using pseudo-biospecific ligands (El-Kak and Vijayalakshmi, 1991 Atkins et al., 2005 Serpa et al., 2005 Kumar et al., 2006). 

---