Protein CSPs

The complex structures of proteins, which have different types of groups, loops and bridges, are responsible for the chiral resolution of racemic compounds. Therefore, a small change in the protein molecule results in a drastic change in enantioselectivity. A few reports are available that indicate that different protein structures are responsible for different chiral resolution capacities. One of the advantages of protein-based CSPs is that chiral chromatography is carried out under the reversed phase mode - that is, aqueous mobile phases are frequently used - and, therefore, there is considerable scope for optimizing chiral resolution. 

Buffers of differing concentrations and pH values are mostly used for chiral resolution on these CSPs, since these phases are stable under the reversed phase mode. With the exception of a few reports where gradient elution was used, the elution is usually carried out in isocratic mode. The most commonly used buffers were phosphate and borate, which were 

CSPs has been reported the hydrophobic interactions are affected by the use of these solvents, the most important of which are methanol, ethanol, 1-propanol, 2-propanol, acetonitrile and THF. These organic modifiers have been used in the range of 1-10%. Care must be taken when using these organic modifiers, as they can denature the protein. However, high concentrations of methanol and acetonitrile have been used on some of the crosslinked protein CSPs. The selection of these organic modifiers depends on the structure of the racemic compounds and the CSP used. In some cases, charged modifiers such as hexanoic acid, octanoic acid and 

The effect of temperature on chiral resolution on protein phases is very cmcial, but few reports are available that deal with this effect. The loading capacities of protein CSPs may be understood from a = 2/ 1 and k = ks + k, where kg and correspond to selective and nonselective contributions. When the amount of the analyte on the CSP increases, the relative contribution of to the observed k values (ki and ka) also increases. The critical selective sites become saturated, resulting in a decrease in the separation factors, because k = Ogja, where and am are 

---

Both the heat and cold shock response are universal and have been studied extensively. The major heat shock proteins (HSPs) are highly conserved. They are involved in the homeostatic adaptation of cells to harsh environmental conditions. Some act as molecular chaperones for protein folding, while others are involved in the processing of denatured polypeptides whose accumulation would be deleterious. The cold shock results in the transient induction of cold shock proteins (CSPs), which include a family of small acidic proteins carrying the cold shock domain. The CSPs appear to be involved in various cellular functions such as transcription, translation and DNA recombination. 

Cysteine string protein (CSP) Cytochrome b561 Peripheral membrane protein that is paimitoylated on >10 cysteines. May have a role in Ca2+ sensitivity of exocytosis. Electron-transport protein required for intravesicular monooxygenases in subsets of secretory vesicles. Required for dopamine- -hydroxylase and peptide amidase activity. 

The ability of proteins to form enantioselective interactions with a large variety of drugs is used in chiral affinity chromatography. Protein CSPs that are most frequently used for the enantioseparation of pharmaceuticals include bovine serum albumin (BSA), human serum albumin... 

Cold-shock proteins (Csps) are transiently expressed at a higher level in bacteria as a response to an abrupt decrease from normal physiological temperature. Their exact biological function is still unknown, but translational regulation, possibly via RNA chaperoning, has been discussed. " Csps from mesophiles and thermophiles differ widely in their stability, but show... 

Synapsins la, lb, Ha, lib Rab3, rabphilin Cysteine string proteins (CSP) Synaptotagmins... 

Wainer et al. [77] presented a CSP based on a-chymotrypsin protein, and, initially, the chiral resolution of certain amino acids and amino ester was achieved on this protein CSP [14,77]. Later, this CSP was used for the chiral resolution of dipeptides and profens [78,79]. Recently, Felix and Descorps [80,81] used immobilized a-chymotrypsin for the chiral resolution of a variety of racemic compounds. Cellobiohydrolase-I (CBH-I) immobilized to silica gel was found to... 

Achieve at least Partial Resolution by Selecting Protein CSP Arbitrarily and Using 5ft mM Phosphate or Other Buffers (pH 7.0)... 

SCHEME 1 The protocol for the development and optimization of mobile phases on protein CSPs. 

The loading capacities of protein CSP may be understood from a = k2/k1 and k = ks + kn, where ks and kn correspond to selective and nonselective contributions, respectively. When the amount of the analyte on CSP increases, the relative... 

Mosbah A., Campanacci V., Lartigue A., Tegoni M., Cambillau C. and Darbon H. (2002) The solution structure of a chemosensory protein (CSP) from the moth Mamestra brassicae. Biochem. J. (e-published, September). 

The odorant-binding proteins (OBPs) and the chemosensory proteins (CSPs) are proteins from the lymph that are thought to accomplish these tasks, solubilizing and protecting the odorant and contact chemosensory molecules. This chapter describes the biochemical and evolutionary aspects of these two families of peripheral sensory proteins of insects. Particular attention will be paid to the subclassification of binding proteins, the diversity of gene structures and the phyletic and molecular relatedness between binding proteins from different insect species. 

Figure 7.15. Functions of cold-shock proteins (Csp s) as RNA chaperones. The model shows how Csp s assist in coupling transcription to translation. Cold-shock proteins bind relatively weakly to nascent mRNA extending from the RNA polymerase complex (RNAP) and maintain the mRNA in a linear form that can be bound to ribosomes and translated into protein. Under nonstressful conditions, the weakly binding Csp s are present at adequate concentrations to perform this chaperoning function. However, during cold stress, the propensity for RNA to form secondary structures that block translation becomes greater. This necessitates that a higher level of Csp s be present in the cell, to ensure that chaperoning of mRNA is effective. (Figure modified after Graumann and Marahiel, 1998.)...

---