Structural and functional characterization of uncoupling
proteins: Alkylsulfonates as probes of UCP transport mechanism

D 2003

Structural and functional characterization of uncoupling proteins: Alkylsulfonates as probes of UCP transport mechanism

VAŘECHA, Miroslav; Martin JABUREK; Lubomi DVORAK; Petr JEZEK; Petr PAUČEK et al.

Základní údaje

Originální název

Structural and functional characterization of uncoupling proteins: Alkylsulfonates as probes of UCP transport mechanism

Autoři

VAŘECHA, Miroslav; Martin JABUREK; Lubomi DVORAK; Petr JEZEK; Petr PAUČEK; Keith GARLID; Stanislav KOZUBEK a Michal KOZUBEK

Vydání

Brno, Biophysics of the Genome, od s. 74-81, 8 s. 2003

Nakladatel

Masaryk University

Další údaje

Jazyk

angličtina

Typ výsledku

Stať ve sborníku

Obor

10600 1.6 Biological sciences

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14330/03:00009012

Organizační jednotka

Fakulta informatiky

ISBN

80-210-3226-X

Klíčová slova anglicky

uncoupling protein

Štítky

uncoupling protein

Příznaky

Mezinárodní význam

Změněno: 29. 10. 2010 14:37, prof. RNDr. Michal Kozubek, Ph.D.

Anotace

V originále

The mechanism of fatty acid-dependent uncoupling by mitochondrial uncoupling proteins (UCP) is still in debate. We have hypothesized that the anionic fatty acid head group is translocated by UCP, and the proton is transported electroneutrally in the bilayer by flip-flop of the protonated fatty acid. Alkylsulfonates are useful as probes of the UCP transport mechanism. They are analogues of fatty acids, and they are transported by UCP1, UCP2 and UCP3. Alkylsulfonates cannot be protonated because of their low pKa; consequently, they cannot catalyze electroneutral proton transport in the bilayer and cannot support uncoupling by UCP. We report that propranolol forms permeant ion pairs with the alkylsulfonates, thereby removing this restriction. Because a proton is transported with the neutral ion pair, the sulfonate is able to deliver protons across the bilayer, behaving as if it were a fatty acid. When ion pair transport is combined with UCP1, we now observe electrophoretic proton transport and uncoupling of brown adipose tissue mitochondria. These experiments confirm that the proton transport of UCP-mediated uncoupling takes place in the lipid bilayer and not through UCP itself. Thus, UCP1, like other members of its gene family, translocates anions and does not translocate protons.

Návaznosti

MSM 143300002, záměr

Název: Využití počítačové analýzy obrazu v optické mikroskopii

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, Využití počítačové analýzy obrazu v optické mikroskopii

Citovat

VAŘECHA, Miroslav; Martin JABUREK; Lubomi DVORAK; Petr JEZEK; Petr PAUČEK; Keith GARLID; Stanislav KOZUBEK a Michal KOZUBEK. Structural and functional characterization of uncoupling proteins: Alkylsulfonates as probes of UCP transport mechanism. In Biophysics of the Genome. Brno: Masaryk University, 2003, s. 74-81. ISBN 80-210-3226-X.

@inproceedings{489666,
   author = {Vařecha, Miroslav and Jaburek, Martin and Dvorak, Lubomi and Jezek, Petr and Pauček, Petr and Garlid, Keith and Kozubek, Stanislav and Kozubek, Michal},
   address = {Brno},
   booktitle = {Biophysics of the Genome},
   keywords = {uncoupling protein},
   language = {eng},
   location = {Brno},
   isbn = {80-210-3226-X},
   pages = {74-81},
   publisher = {Masaryk University},
   title = {Structural and functional characterization of uncoupling proteins: Alkylsulfonates as probes of UCP transport mechanism},
   year = {2003}
}

TY  - CONF
ID  - 489666
AU  - Vařecha, Miroslav - Jaburek, Martin - Dvorak, Lubomi - Jezek, Petr - Pauček, Petr - Garlid, Keith - Kozubek, Stanislav - Kozubek, Michal
PY  - 2003
TI  - Structural and functional characterization of uncoupling proteins: Alkylsulfonates as probes of UCP transport mechanism
PB  - Masaryk University
CY  - Brno
SN  - 802103226X
KW  - uncoupling protein
N2  - The mechanism of fatty acid-dependent uncoupling by mitochondrial uncoupling proteins (UCP) is still in debate. We have hypothesized that the anionic fatty acid head group is translocated by UCP, and the proton is transported electroneutrally in the bilayer by flip-flop of the protonated fatty acid. Alkylsulfonates are useful as probes of the UCP transport mechanism. They are analogues of fatty acids, and they are transported by UCP1, UCP2 and UCP3. Alkylsulfonates cannot be protonated because of their low pKa; consequently, they cannot catalyze electroneutral proton transport in the bilayer and cannot support uncoupling by UCP. We report that propranolol forms permeant ion pairs with the alkylsulfonates, thereby removing this restriction. Because a proton is transported with the neutral ion pair, the sulfonate is able to deliver protons across the bilayer, behaving as if it were a fatty acid. When ion pair transport is combined with UCP1, we now observe electrophoretic proton transport and uncoupling of brown adipose tissue mitochondria. These experiments confirm that the proton transport of UCP-mediated uncoupling takes place in the lipid bilayer and not through UCP itself. Thus, UCP1, like other members of its gene family, translocates anions and does not translocate protons.
ER  -

VAŘECHA, Miroslav; Martin JABUREK; Lubomi DVORAK; Petr JEZEK; Petr PAUČEK; Keith GARLID; Stanislav KOZUBEK a Michal KOZUBEK. Structural and functional characterization of uncoupling proteins: Alkylsulfonates as probes of UCP transport mechanism. In \textit{Biophysics of the Genome}. Brno: Masaryk University, 2003, s.~74-81. ISBN~80-210-3226-X.

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