Journal article
The pH dependence of the 695 nm charge transfer band reveals the population of an intermediate state of the alkaline transition of ferricytochrome c at low ion concentrations
Biochemistry (Easton), v 48(13), pp 2990-2996
07 Apr 2009
PMID: 19222214
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
We have measured and analyzed the pH dependence of the 695 nm charge transfer band of horse heart ferricytochrome c as a function of pH between 7.0 and 10.5 at high (50 mM) and low (0.5 mM) phosphate ion concentrations. Our data clearly reveal that the transition from the native state (III) to the two alkaline states (IV) involves two deprotonation steps which cannot be assigned to the two different lysine ligands associated with the two alkaline states. While the respective pK values are rather similar at high phosphate concentrations (9.23 and 9.14), they are clearly different at low anion concentrations (9.65 and 8.5). Apparently, the deprotonation that can be assigned to a pK of 8.5 populates an intermediate state termed III*, in which M80 is still an axial ligand. A comparison of Soret band CD spectra suggests that III* bears some similarity with the recently characterized thermally excited state IIIh. Our data suggest that the current picture of the alkaline transition is incomplete. The obtained results might be of relevance for characterizing the structure of ferricytochrome c bound to anionic phospholipids.
Metrics
Details
- Title
- The pH dependence of the 695 nm charge transfer band reveals the population of an intermediate state of the alkaline transition of ferricytochrome c at low ion concentrations
- Creators
- Daniel Verbaro - Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, USAAndrew HagarmanJonathan SofferReinhard Schweitzer-Stenner
- Publication Details
- Biochemistry (Easton), v 48(13), pp 2990-2996
- Publisher
- American Chemical Society; Washington, DC
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemistry
- Web of Science ID
- WOS:000264758500015
- Scopus ID
- 2-s2.0-65249127460
- Other Identifier
- 991014878157204721
UN Sustainable Development Goals (SDGs)
This publication has contributed to the advancement of the following goals:
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Biochemistry & Molecular Biology