N-Histidine

The development and use in peptide synthesis of the 1-adamantyloxymethyl protecting group for N -histidine 28 was reported <9 CS(P1)2139>. A procedure for the regiospecific alkylation of histidine and histamine at N-l(t) via the corresponding tetrahydro oximidazo[l,5-c]pyrimidines 29 was also developed <96T5363>. 

It could be said that we have not offered proof of the postulate that the iron-histidine distance is altered. In one sense this is not true for we have found that the Mossbauer spectrum of the iron(III) is altered by pH and ionic strength changes. This is a probe of the iron nucleus. However it would be better to have a probe of the nitrogen or the hydrogens of the imidazole. This is now available through the refinement of NMR techniques. Other possibilities are the use of cobalt(II) porphyrin as a probe to examine the Co(II)—N (histidine) distance through EPR super-hyperfine structure studies, and the use of Mn(III) porphyrin for the... 

Kanesaki, Y., Yamamoto, H., Paithoonrangsarid, K., Shoumskaya, M., Suzuki, I., Hayashi, H. and Murata, N. Histidine kinases play important roles in the perception and signal transduction of hydrogen peroxide in the cyanobacterium Synechocystis sp. PCC 6803. Plant J, 49 (2007) 313-324. 

Scheme 1 Catalytic cycle for the hydroxylation of tyrosine and the oxidation of DOPA. N = histidine residues (axial ligands at the coppeis were omitted fin clarity) R = alanine...

Rashkovetskii, L. G., Prozorovskii, V. N. (1983). Kinetic properties and functional role of domains of Micrococcus sp.n histidine decarboxylase. Biokhimiia, 48, 297-304. 

Camosinase. Camosinase is an enzyme that splits carnosine, a naturally occurring peptide, /S-alanyl-n-histidine. A preparation that is... 

In contrast with these findings for cobalt(u) complexes of octahedral configuration, the interaction of Oa with a cobalt(n) histidine complex has been investigated in strongly basic media. In solutions of IM-NaOH, the spectrum of the cobalt(n) species is consistent with that of a tetrahedral complex with four nitrogen donors. The rate law for the reaction is... 

The biological lability of the a-amino group of histidine has been shown in various ways. It is not nutritionally essential that histidine be fed intact. In the rat imidazolelactic acid - - and imidazolepyruvic acid - can be substituted for it. n-Histidine can be converted to form the L-isomer. ... 

X = N (Histidine) Hemoglobin, Myoglobin, Peroxidase X = O (Tyrosine) Catalase... 

Urocanic acid has been isolated from the urine of various animals fed n-histidine (see 230 for older references). None was obtained from D-histidine 231). Reports that urocanic acid was excreted following subcutaneous injection of histidine could not be confirmed 230). Furthermore, the older work has been criticized because of inadequate isolation methods. 

The characterization of complexes of various amino acids containing -OH (serine, threonine, tyrosine) [6,8,17,30] or -COOH groups (aspartic and glutamic acids) [6] and -NH2 (lysine, ornithine) [31,32] or imidazole N (histidine, histamine) [3,6,33-38] has been published. 

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