Histidyl peptides

Faraggi M, BetteUieim A. (1977) The reaction of the hydrated electron with amino acids, peptides, and proteins in aqueous solutions 111. Histidyl peptides. RadiatRes7 311-324. 

In interference studies carried out on this system assaying the spike of free histidine and small histidyl peptides, Hungerford et al. (1990) suggested the use of an anion-exchange minicolumn (MC) placed in-line with the carrier stream, which, along with... 

Tryptophan cleavage with NBS can be blocked by reaction of the tryptophan peptide or protein with 2-hydroxy-5-nitrobenzyl bromide the Koshland reagent (see Section III.4.) or by ozonolysis of tryptophan residues to formylkynurenine (313, 419). These modification reactions of the indole nucleus restrict NBS cleavage to tyrosyl and histidyl peptide bonds. 

Peptides containing histidyl groups were prepared and their catalytic activities discussed121 ... 

A review3 with 57 references discusses the interaction of Ptn and Pd11 with histidine and histidyl containing peptides. The coordinating behavior of histidyl containing peptides towards Pt11 and Pd11 depends on the histidyl position in the peptide sequence. 

Angiotensin-I converting enzyme (ACE) controls blood pressure by catalyzing the hydrolysis of two amino acids (His-Leu) at the C-terminus of angiotensin-I to produce a vasoconstrictor, angiotensin-II. The enzyme can also hydrolyze a synthetic substrate, hippuryl-L-histidyl-L-leucine (HHL), to hippuric acid (HA). At four different concentrations of HHL solutions (pH 8.3), the initial rates of HA formation (pmolmin" ) are obtained as shown in Table P3.8. Several small peptides (e.g., Ile-Lys-Tyr) can reversibly inhibit the ACE activity. The reaction rates of HA formation in the presence of 1.5 and 2.5 pmoll of an inhibitory peptide (Ile-Lys-Tyr) are also given in the table. 

Recently the structures of silver(I) complexes with cyclo-(glycyl-L-histidyl), cyclo-(L-methionyl-L-histidyl) and cyclo-(L-histidyl-L-histidyl) were examined using 7H and 13CNMR spectroscopy. The NMR measurements suggested that the silver ion was bound to the sulfur atom of the thioether and to the nitrogen atom of imidazole groups in these cyclic peptides, but not to their amide groups.417... 

Another interesting feature of the transit peptide of the type-L phosphorylase isozyme is the high content of histidine the peptide contains five histidyl residues in a total of 50 amino acid residues, in contrast to other transit peptides that contain no or little, if any, histidyl residues. It is not known if these residues have any special role other than increasing the positive charge of the peptide. 

Table V summarizes the reduction activity of acetylene with the Co(II)-complex catalysts of various sulfhydryl-containing peptides. Of interest is the high activity of the sulfhydryl- and imidazole-containing peptides such as N-mercaptoacetyl-L-histidine and N-mercaptoacetyl-DL-histidyl-DL-histidine. In addition, the effect of amino-acid residues on the reduction of acetylene with these Co(II) complexes decreases in the order histidine > glycine > cysteine > tryptophan.

Wei, Y., Pirollo, K.F., Yu, B., Rait, A., Xiang, L., Huang, W., Zhou, Q., Ertem, G., and Chang, E.H. (2004) Enhanced transfection efficiency of a systemically delivered tumor-targeting immunolipoplex by inclusion of a pH-sensitive histidylated oligolysine peptide. Nucleic Acids Res. 32 e48. 

Figure 9.24 HPLC separation of a standard mixture of fiuorescamine derivatives of histidine, leucine, and histidyl-leudne (fl). HPLC separation of enzymatically formed peptide fragments in the presence (A, C) and absence, D,E) of sodium chloride in the incubation mixture. (From Baranowski et al., 1982.)...

Fia. 28. Structure of histidyl-8-o-FAD (left) and the sequence of the flavin penta-peptide (right) of succinate dehydrogenase. From Singer et al. (SB). 

As a result of collaborative work among the laboratories of Ehren-berg, Hemmerich, and Singer 161-163), the structure of the bound flavin was elucidated to be 8 -(A(-3-histidyl) flavin adenine dinucleotide. The structure of the histidyl flavin and the sequence of a flavin-bound penta-peptide isolated by proteolytic digestion are shown in Fig. 28. Singer et al. 23,25) have discussed the details of these studies. 

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