2023年11月22日 · Histidine is usually referred to as a semi-essential amino acid because it is nonessential in adults but is essential in the diet of infants and individuals with uremia - a …

2023年7月30日 · Histidine’s imidazole side chain is unique amongst amino acids, giving rise to its aromaticity and amphoteric properties at physiologic pH. This property makes histidine a key …

It contains an α-amino group (which is in the protonated –NH 3 + form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO − form under …

The imidazole side chain of histidine can adopt two tautomeric forms and can ionize at near-neutral pH. Thus, histidine plays a key role in many enzymatic reactions and processes …

2013年3月1日 · The side chain imidazole of histidine is an aromatic motif; an ionizable group with the acidic ionization constant around pK a =6.5; a coordinating ligand of metallic cations (for …

The 15 N chemical shifts of His side chains are highly dependent on the tautomeric state of the imidazole ring, which in turn depends on the pH of the sample (62,82,83).

2011年1月5日 · Here we use magic-angle-spinning solid-state NMR spectroscopy to determine the 15 N, 13 C, and 1 H chemical shifts of histidine from pH 4.5 to 11. Two-dimensional …

2024年8月5日 · Histidine is a key amino-acid residue in proteins with unique properties engendered by its imidazole side chain that can exist in three different states: two different …

2014年7月17日 · It is well known that histidine is involved in many biological functions due to the structural versatility of its side chain. However, probing the conformational transitions of …

Histidine is an essential amino acid that plays a vital role in the biosynthesis of proteins. It comprises a carboxylic acid group, α-amino group, and an imidazole side chain thus labelling …