Proteins carbodiimide hydrochloride

COOH groups of the PE (PAA or PGA) and the -NH2 moieties of the pre-loaded protein, using l-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) as a catalyst [99]. Negligible enzyme desorption (<0.1 %) is observed from cross-linked lysozyme-loaded MS spheres after exposing the samples to an aqueous solution for 48 h, while about 25 % of the immobilized lysozyme is desorbed under the same conditions when the lysozyme is not cross-linked. 

NPH HCl) with l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC HCl) as a coupling agent [593,594], The advantage is that with hydrazines it is possible to carry out the derivatization in milder conditions. An efficient postcolumn derivatization is obtained using avidin or streptavidin. In fact, these two proteins react in a very specific way with biotin, therefore they are bound with a fluorescent marker, such as fluorescein 5-isothiocyanate (FITC) to obtain fluorescent derivatives. Some authors [595] report the use of MS or MS/MS for biotin detection, but this method seems to be less sensitive than FLD. 

Modification of the protein amine groups is the procedure most frequently used to produce antibody-liposome conjugates. Early procedures used crosslinking agents, such as l-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) (27,28) in the presence of preformed liposomes containing a lipophilic carboxylic acid. Condensing agents like these tend to form protein-protein polymers. Control of these reactions is typically difficult and complex, and as a result separation of the liposomes from protein polymers is a... 

Direct detections of E. coli have been demonstrated since 1998, when Fratamico et al. demonstrated the detection of viable E. coli 0157 H7 using a Biacore system [18]. They compared two sensing platforms, both based on attachment via Ar-ethyl-ArC(diniethylaminopropyl)carbodiimide hydrochloride (EDC) and AT-hydroxy-succinimide (NHS) chemistry. Monoclonal or polyclonal antibody was bound directly to the sensing surface or was immo-Irilized on a bound layer of protein A or protein G. Using a sandwich assay, as seen in Fig. 1, a lower limit of detection of 5-7 x 10 cfu/mL was demonstrated. 

Ferritin and bovine serum albumin (BSA) proteins can also chemically bond to nitrogen-doped MWNTs (CNx-MWNTs) through a two-step process of diimide-activated amidation. Firstly, carboxylated CNx-MWNTs were activated by N-ethyl-N -(3-dimethylaminopropyl)carbodiimide hydrochloride (EDAC), forming a stable active ester in the presence of N-hydroxysuccinimide (NHS). Secondly, the active ester was reacted with the amine groups on the proteins of ferritin or BSA, fornting an antide bond between the CNx-MWNTs and proteins. This two-step process avoids the intermolecular conjugation of proteins, and guarantees the uniform attachment of proteins on NTs (Scheme 12.3) [44]. 

Carbodiimides are, in general, useful compounds for effecting certain dehydrative condensations, e.g., in the formation of amides, esters, and anhydrides. These two crystalline water-soluble carbodiimides are especially useful in the synthesis of peptides and in the modification of proteins. The excess of reagent and the co-product (the corresponding urea) are easily separated from products with limited solubility in water. The hydrochloride is best employed in nonaqueous solvents (methylene chloride, acetonitrile, dimethylformamide). The methiodide is relatively stable in neutral aqueous systems, and thus is recommended for those media. 

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