Logo image
Kinetic and spectroscopic studies of haemoglobin and myoglobin from Urechis caupo. Distal residue effects
Journal article   Open access   Peer reviewed

Kinetic and spectroscopic studies of haemoglobin and myoglobin from Urechis caupo. Distal residue effects

T J DiFeo, A W Addison and J J Stephanos
Biochemical journal, v 269(3), pp 739-747
01 Aug 1990
PMID: 2167663
url
https://doi.org/10.1042/bj2690739View
Published, Version of Record (VoR)Open Access (License Unspecified) Open

Abstract

Animals Carbon Monoxide - metabolism Circular Dichroism Electron Spin Resonance Spectroscopy Elephants Hemoglobins - metabolism Humans Invertebrates - metabolism Isoelectric Focusing Kinetics Methemoglobin - metabolism Metmyoglobin - metabolism Myoglobin - metabolism Nitric Oxide - metabolism Oxidation-Reduction Oxygen - metabolism Spectrophotometry - methods Sulfhydryl Compounds - metabolism
Seven components of the tetrameric haemoglobin (Hbu) from Urechis caupo were separated by preparative isoelectric focusing and characterized by their absorption spectra and pI values. The helix content and Soret delta epsilon values are reported for several of the components. Temperature-jump O2-binding kinetics of the major components of Hbu show biphasic behaviour, with the majority species having kon = 1.57 x 10(9) mol-1.s-1 and koff = 3.32 x 10(4) s-1. The Fourier-transform i.r. spectrum of pooled Hbu(II)-CO displays a stretching frequency of 1942 cm-1. E.s.r. of Hbu(II)-NO demonstrates evidence of proximal strain similar to that encountered in T-state human haemoglobin. CO-driven reduction of U. caupo methaemoglobin, Hbu(III) and U. caupo metmyoglobin [Mbu(III)] shows much higher rates relative to haemoglobins and myoglobins known to possess a distal histidine residue. Nitrosyl auto-reduction kinetics of Hbu(III)-NO and Mbu(III)-NO are examined. The equilibrium binding constants of several ligands are reported for both Hbu and Mbu, and together with the above kinetic data suggest differences in haem pocket environments between Hbu and Mbu. Reaction of Hbu with 2-chloromercuri-4,6-dinitrophenol demonstrates the presence of one reactive thiol group per globin chain. lambda max. values and the respective molar absorption coefficients for selected ligand-bound states are reported for the major component of Hbu and for Mbu. The majority haem orientation in U. caupo haemoglobin is identical with that of human haemoglobin.

Metrics

14 Record Views
8 citations in Scopus

Details

UN Sustainable Development Goals (SDGs)

This publication has contributed to the advancement of the following goals:

#3 Good Health and Well-Being

InCites Highlights

Data related to this publication, from InCites Benchmarking & Analytics tool:

Collaboration types
Domestic collaboration
Web of Science research areas
Biochemistry & Molecular Biology
Logo image