Carboxyl groups in proteins

The Derivative, 5-(biotinamido)pentylamine, contains a 5-carbon cadaverine spacer group attached to the valeric acid side chain of biotin (Thermo Fisher). The compound can be used in a carbodi-imide reaction process to label carboxylate groups in proteins and other molecules, forming amide bond linkages (Chapter 3, Section 1). However, the main use of this biotinylation reagent is in the determination of factor XHIa or transglutaminase enzymes in plasma, cell, or tissue extracts. 

Carbodiimides are also used to investigate the conjugation of proteins in structural studies. Also, quantification of carboxyl groups in proteins can be achieved with carbodiimides. Numerous examples of proteine modification by carbodiimides are discussed in Section 13.2.3. 

Water-soluble carbodiimide for die modification of carboxyl groups in proteins zero-length crosslinking proteins activation of carboxyl groups for amidation reactions, as for the coupling of amino-nucleotides to mattices for DNA microarrays. 

Hoare DG, Koshland DE. A procedure for selective modification of carboxyl groups in proteins. J. Am. Chem. Soc. 1966 88 2057. DeMar JC, Disher RM, Wensel TG. HPLC analysis of protein-linked fatty acids using fluorescence detection of 4-(diazo-methyl)-7-diethyl aminocoumarin derivatives. FASEB J. 1992 61 A81. 

USE Reagent for the detection of free amino and carboxyl groups in proteins and peptides, yielding a blue color under the proper Conditions. Monograph Henri Plagnol, Influence de la Structure des Composes Amines dans leur Reaction awe la Ninhytfrine (Bordeaux, 1962) 156 pp. 

In addition, bioconjugation of fluorescent probes may be enabled through a variety of functional group activation chemistries as a means to facilitate bioconjugation. For instance, carboxyl-reactive probes can combine with carboxyl groups in proteins, peptides. 

It is very interesting, that the sequence of the alkali cations is quite the reverse of that characteristic of the carboxyl colloids of 2d (seep.284, Fig. 14), further that the sequence obtained with the alkaline earth cations is also different, a characteristic transition sequence occurring. All this shows that the ionised carboxyl group in proteins is more polarisable than the same group in the carboxyl colloids of 2d. We have here once more a characteristic example of constitutional influences on the polarisability of the ionised groups, discussed already in 2k (p. 292). 

The alkaline treatment is an effective analytical extraction technique for extracellular biopolymers from biomass, where NaOH is the most commonly used base. The increase in pH with alkaline addition induces the formation of anionic charges from carboxylic groups in proteins and polysaccharides, destabilizing the sludge floes. 

Protein Modification. Carboxyl groups in proteins react with EDC, resulting in an activated group that can be trapped with a nucleophile such as glycine methyl ester. The nucleophile can... 

Reduction of Carboxylic Acids to Alcohols. The conversion of carboxylic acids to alcohols occurs in a two-step process under mild conditions using reagent K with yields for simple alcohols ranging from 50-100%. The reduction of a dipeptide (eq 7) suggests a potential utility in modifying carboxyl groups in proteins. 

There are various chemical functional groups that would attract and sequester the metals in biomass acetamido groups of chitin, structural polysaccharides of fungi, amido, amino, sulphydryl and carboxyl groups in proteins, hydroxyls in polysaccharide and mainly carboxyls and sulfates in polysaccharides of marine algae that belong to the divisions Phaeophyta, Rhodophyta and Chlorophyta. 

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