Raman marker bands of metal coordination sites of histidine side chains in peptides and proteins

✍ Scribed by Takashi Miura; Tamami Satoh; Ayako Hori-i; Hideo Takeuchi

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 434 KB
• Volume: 29
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(199801)29:1<41::aid-jrs212>3.0.co;2-r

✦ Synopsis

Raman spectra were measured for metal complexes of amino acid histidine and histidine-containing peptides. The stretching band of the histidyl imidazole ring appears in the 1606-1594 cm-1 region when the atom of C 4 xC 5 N Ó the imidazole ring acts as a ligand of the metal coordination and the atom is protonated, whereas it appears in a N n lower wavenumber region, 1588-1573 cm-1, when the metal coordination takes place via with being proto-N n N Ó nated. These wavenumbers are generally higher than those of the corresponding and tautomeric N n -N Ó -protonated forms of metal-free histidine. Upon N-deuteration, the stretching mode shows downshifts of about 25 and C 4 xC 5 10 cm-1 for and complexes, respectively. Raman bands at ca. 1430 and ca. 1275 cm-1 (ca. 1350 N Ó -N n -metal and ca. 1265 cm-1 for N-deuterated histidine) gain intensity upon binding of metal to and respectively, and N Ó N n , they may also serve as markers of the metal coordination site. In the Raman spectrum of a 27mer zinc Ðnger peptide that contains two histidine residues, the stretching band is identiÐed at ca. 1606 cm-1 in C 4 xC 5 H 2 O solution and an intense band is observed at 1342 cm-1 in solution. These observations are consistent with the D 2 O zinc coordination by the histidyl atom in the zinc Ðnger. The histidyl Raman marker bands of metal coordi-N Ó nation found here may be useful in analyzing metal-histidine interactions in peptides and proteins. 1998 John ( Wiley & Sons, Ltd.