Proton NMR investigation of heme and surrounding proton in low-spin cyanide-ligated bacterial hemoglobin from Vitreoscilla

Youlin Xia, Jihui Wu, Shouhong Guang, Haiyang Zhang, Shan Liang, Yunyu Shi

Research output: Contribution to journalArticlepeer-review

Abstract

1H NMR spectra of low-spin cyanide-ligated bacterial hemoglobin from Vitreoscilla (VtHb-CN) are reported. The assignments of the 1H NMR spectra of VtHb-CN have been made through MCOSY, NOESY, 1D TOE and SUPERWEFT experiments. Almost all resonance peaks of heme and ligated His85 are identified. The spin-lattice relaxation time T1's and the variation relationships of chemical shifts of these peaks with temperature have been acquired, from which the distances between the measured protons and Fe3+, and the diamagnetic chemical shifts have been acquired, respectively. The ionization constants of pKa's of ligated His85 are determined through pH titration of chemical shift, which is 4.95 for ligated His85 C2H proton. The lower pKa is attributed to the influence of the Fe3+ of carrying positive charge and the coordination of His85 and Fe3+ of heme.

Original languageEnglish (US)
Pages (from-to)65-67
Number of pages3
JournalScience in China, Series C: Life Sciences
Volume43
Issue number1
StatePublished - Dec 1 2000

Keywords

  • Hemoglobin
  • NMR
  • Relaxation
  • VtHb-CN
  • pK

Fingerprint Dive into the research topics of 'Proton NMR investigation of heme and surrounding proton in low-spin cyanide-ligated bacterial hemoglobin from Vitreoscilla'. Together they form a unique fingerprint.

Cite this