Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Insertion of Heme b into the Structure of the Cys34-Carbamidomethylated Human Lipocalin a1-Microglobulin: Formation of a [(Heme)2(a1-Microglobulin)]3 Complex

Siebel, Judith F. ; Kosinsky, Robyn L. ; Åkerström, Bo LU and Knipp, Markus (2012) In ChemBioChem 13(6). p.879-887
Abstract
a1-Microglobulin (a1m) is a 26 kDa plasma and tissue protein belonging to the lipocalin protein family. Previous investigations indicate that the protein interacts with heme and suggest that it has a function in heme metabolism. However, detailed characterizations of the a1mheme interactions are lacking. Here, we report for the first time the preparation and analysis of a stable a1mheme complex upon carbamidomethylation of the reactive Cys34 by using recombinantly expressed human a1m. Analytical size-exclusion chromatography coupled with a diode-array absorbance spectrophotometry demonstrates that at first an a1mheme monomer is formed. Subsequently, a second heme triggers oligomerization that leads to trimerization. The resulting... (More)
a1-Microglobulin (a1m) is a 26 kDa plasma and tissue protein belonging to the lipocalin protein family. Previous investigations indicate that the protein interacts with heme and suggest that it has a function in heme metabolism. However, detailed characterizations of the a1mheme interactions are lacking. Here, we report for the first time the preparation and analysis of a stable a1mheme complex upon carbamidomethylation of the reactive Cys34 by using recombinantly expressed human a1m. Analytical size-exclusion chromatography coupled with a diode-array absorbance spectrophotometry demonstrates that at first an a1mheme monomer is formed. Subsequently, a second heme triggers oligomerization that leads to trimerization. The resulting (a1m[heme]2)3 complex was characterized by resonance Raman and EPR spectroscopy, which support the presence of two ferrihemes, thus indicating an unusual spin-state admixed ground state with S=3/2, 5/2. (Less)
Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
heme proteins, homotrimers, lipocalin, metalloproteins, microglobulins, spin admixture
in
ChemBioChem
volume
13
issue
6
pages
879 - 887
publisher
John Wiley & Sons Inc.
external identifiers
  • wos:000302609100018
  • scopus:84859597177
ISSN
1439-4227
DOI
10.1002/cbic.201100808
language
English
LU publication?
yes
id
9010a33b-8c6d-485c-9698-4cebf013e68a (old id 2571583)
date added to LUP
2016-04-01 09:56:43
date last changed
2022-01-25 18:15:21
@article{9010a33b-8c6d-485c-9698-4cebf013e68a,
  abstract     = {{a1-Microglobulin (a1m) is a 26 kDa plasma and tissue protein belonging to the lipocalin protein family. Previous investigations indicate that the protein interacts with heme and suggest that it has a function in heme metabolism. However, detailed characterizations of the a1mheme interactions are lacking. Here, we report for the first time the preparation and analysis of a stable a1mheme complex upon carbamidomethylation of the reactive Cys34 by using recombinantly expressed human a1m. Analytical size-exclusion chromatography coupled with a diode-array absorbance spectrophotometry demonstrates that at first an a1mheme monomer is formed. Subsequently, a second heme triggers oligomerization that leads to trimerization. The resulting (a1m[heme]2)3 complex was characterized by resonance Raman and EPR spectroscopy, which support the presence of two ferrihemes, thus indicating an unusual spin-state admixed ground state with S=3/2, 5/2.}},
  author       = {{Siebel, Judith F. and Kosinsky, Robyn L. and Åkerström, Bo and Knipp, Markus}},
  issn         = {{1439-4227}},
  keywords     = {{heme proteins; homotrimers; lipocalin; metalloproteins; microglobulins; spin admixture}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{879--887}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{ChemBioChem}},
  title        = {{Insertion of Heme b into the Structure of the Cys34-Carbamidomethylated Human Lipocalin a1-Microglobulin: Formation of a [(Heme)2(a1-Microglobulin)]3 Complex}},
  url          = {{http://dx.doi.org/10.1002/cbic.201100808}},
  doi          = {{10.1002/cbic.201100808}},
  volume       = {{13}},
  year         = {{2012}},
}