Amino groups in proteins

Bolton, J. L. Turnipseed, S. B. Thompson, J. A. Influence of quinone methide reactivity on the alkylation of thiol and amino groups in proteins studies utilizing amino acid and peptide models. Chem.-Biol. Interact. 1997, 107, 185-200. 

Watkins NG, Thorpe SR, Baynes JW. Glycation of amino groups in protein. Studies on the specificity of modification of RNase by glucose. J. Biol. Chem. 1985 260 10629-10636. 

TNBS has been used to measure the free amino groups in proteins (Habeeb, 1966 Kakade and Liener, 1969), as a qualitative check for the presence of amines, sulfhydryls, or hydrazides (Inman and Dintzis, 1969), and to specifically determine the number of s-amino groups of L-lysine in carrier proteins (Sashidhar et al., 1994). 

Habeeb, A.F.S.A. (1966) Determination of free amino groups in protein by trinitrobenzene sulfonic acid. Anal. Biochem. 14, 328. 

Singh, R. et al. (1996) Formation of N-subsdtuted 2-iminothiolanes when amino groups in proteins and peptides are modified by 2-iminothiolane. Anal. Biochem. 236(1), 114-125. 

The chemical structure of 2,5-hexanedione suggested that it could react with lysine side-chain amino groups in proteins to form pyrroles (see Figure 2-7). In vitro experiments showed that this was, in fact, the case, and that the modified proteins can undergo secondary reactions to yield oxidized and polymeric products (DeCaprio et al. 1982 Graham et al. 1982). Oral administration of 2,5-hexanedione produced evidence that this process can take place in vivo as demonstrated by the detection of 2,5-dimethylpyrrole adducts in serum and axonal cytoskeletal proteins (DeCaprio and O Neill 1985). When a series of... 

The addition of an amine to the carbonyl group of an aldehyde yields—after removal of water—an aldimine (not shown see p. 178). Aldimines are intermediates in amino acid metabolism (see p. 178) and serve to bond aldehydes to amino groups in proteins (see p. 62, for example). The addition of an alcohol to the carbonyl group of an aldehyde yields a hemiacetal (R-O-C(H)OH-R). The cyclic forms of sugars are well-known examples of hemi-... 

Labelling Chemistry and Sequencing. The two main groups for labelling proteins are amine reactive and thiol reactive. For reaction with the amino groups in proteins the fluorophore is converted into the succinimidyl ester derivative by reaction with iV-hydroxysuccinimide, e.g. (3.74), and for reaction with thiols group this is achieved by making iodoacetamide or maleimide derivatives, e.g. (3.75). 

A versatile reagent for introducing sulfhydryl groups into proteins is SATA, N-suc-cinimidyl S-acetylthioacetate (Duncan etal., 1983). The active NHS ester end of SATA reacts with amino groups in proteins and other molecules to form a stable amide linkage (Fig. 54) (Chapter 2, Section 1.4). The modified protein then contains a... 

Reversible Modifying Reagents for Amino Groups in Proteins... 

Several reversible blocking reagents for amino groups in proteins have been reported (see Table I). Succinyl derivatives cannot be removed easily from succinylated proteins under mild conditions however, Braunitzer et al. (43) have shown that tetrafluorosuccinyl derivatives could be removed at pH 9.5 and 0°C (see Reaction 1) ... 

Alternatively, free amino groups of lysine side-chains may be oxidized. Thus the fluorescamine assay is used to measure the extent of loss of amino groups in proteins. 

Figure 13.5. Stractme of mitotane, its acyl chloride conversion product formed by the enzyme cytochrome P450 1 IB (CYPl IB), and the reaction products of the latter with amino groups in proteins or nucleic acids. CYP1 IB occurs in the mitochondria within the adrenal cortex, rendering this tissne (and its derived tissues) selectively susceptible to mitotane.

The covalent coupling of a serine protease to a soluble-insoluble polymer (Eudragit) is also accomplished using a water soluble carbodiimide. Mycotoxins in foods often contain carboxyl groups suitable for carbodiimide mediated coupling with amino groups in proteins useful for developing immunoassay methods. " ... 

Derived from oxidative modification of triose phosphate during glucose metabolism model for glycation of proteins reacts with amino groups in proteins and nucleic acids involved in advanced glycation endproducts. 

The following method for the spectrophotometric determination of amino groups in proteins with TNBS is based on the procedure of Plapp et al. (1971). 

Reversible modification of amino groups in proteins by acid anhydrides. ... 

One of the best-known toxic alkylating agents is mustard gas, an early chemical warfare agent that caused an estimated 400,000 casualties in World War I. A primary halide, mustard gas is highly reactive toward 8 2 displacements by nucleophilic amino groups in proteins. It is thought to act through an intermediate sulfonium ion in much the same manner as S-adenosylmethionine. 

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