Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2012 Sep;9(9):1621-34.
doi: 10.1002/cbdv.201200010.

Kinetic and thermodynamic effects of mutations of human sulfite oxidase

Asha Rajapakshe  1 , Gordon Tollin, John H Enemark
Affiliations
Review

Kinetic and thermodynamic effects of mutations of human sulfite oxidase

Asha Rajapakshe et al. Chem Biodivers. 2012 Sep.
No abstract available

PubMed Disclaimer

Figures

Figure 1
Figure 1
Proposed catalytic cycle for the oxidation of sulfite by hSO [11]
Figure 2
Figure 2
Kinetic transient obtained at 555 nm upon photoexcitation of a solution containing wild-type human SO, dRF, and 0.5 mM fresh semicarbazide hydrochloride (pH 7.4). The portion of the figure outlined by the orange box points to the initial heme reduction by dRFH•; this process is pseudo-first-order, and its rate depends on protein concentration. The dark blue box points to heme reoxidation due to the subsequent IET between the Mo and Fe centers; this process is independent of protein concentration, consistent with its intraprotein nature. The red solid line indicates a single-exponential fit to the IET phase. Keq = b/a. Reproduced with permission from ref [8]. Copyright 2007 Elsevier B.V.
Figure 3
Figure 3
View into the interaction site of K322. The numbers in red are human numbering; black are chicken. The light grey is the phosphate group of Moco.
Figure 4
Figure 4
IET rate constants for wt and K322R mutant at different pH values.
Figure 5
Figure 5
(A) The electrostatic potential map of one of the subunits of SO contoured at color scale data range set to −10 eV and +10 using the VMD [46] program. The structural arrangement of Y273, W338, and H337 residues of interest in the active site of cSO is shown with residues numbered according to the hSO sequence. (B) Schematic representation of the pocket that allows access to the Mo active site from the solvent. The geometrical arrangement of W338 and H337 residues with respect to the anion-binding pocket and to the Mo active site is shown. Only the side chains of Y273, W338 and H337 are pictured. Reproduced from [21]
Figure 6
Figure 6
IET rate constants for wt and mutants of aromatic residues at pH 7.4.
Figure 7
Figure 7
Electrochemical heme midpoint potentials for hSO and mutants at pH 7.4.
See this image and copyright information in PMC

References

    1. Rupar CA, Gillett J, Gordon BA, Ramsay DA, Johnson JL, Garrett RM, Rajagopalan KV, Jung JH, Bacheyie GS, Seller AR. Neuropediatrics. 1996;27:299–304. - PubMed
    1. Schwahn BC, Galloway PG, Bowhay S, Veldman A, Santamaria JA, Schwarz G, Belaidi AA. J. Inher. Metab. Dis. 2010;33:S29–S39.
    1. Kisker C, Schindelin H, Pacheco A, Wehbi W, Garrett RM, Rajagopalan KV, Enemark JH, Rees DC. Cell. 1997;91:973–983. - PubMed
    1. Johnson-Winters K, Tollin G, Enemark JH. Biochemistry. 2010;49:7242–7254. - PMC - PubMed
    1. Johnson-Winters K, Nordstrom AR, Emesh S, Astashkin AV, Rajapakshe A, Berry RE, Tollin G, Enemark JH. Biochemistry. 2010;49:1290–1296. - PMC - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources