Thermal Stability of Dopamine Transporters

Thermal Stability of Dopamine Transporters The thermal stabilities of the rat and mouse dopamine transporter (DAT) proteins were studied within the temperature range of 0–37 °C. The inactivation of the protein was followed by monitoring changes in radioligand-specific binding. We found that the process followed a rate equation with first-order kinetics and was characterized by having a single rate constant k inact. The activation energies (E a) that were calculated from the Arrhenius plots (ln k inact vs. 1/T) were 43 ± 5 and 45 ± 6 kJ/mol for the rat (rDAT) and mouse (mDAT) transporters, respectively, and 44 ± 7 kJ/mol for rDAT from PC-6.3 cell line. These E a values were similar to the E a values of thermal inactivation of the muscarinic receptor from rat brain cortex and to the thermal inactivation of other transmembrane proteins. However, all of these activation energy values were significantly lower than the E a values for soluble single-subunit proteins of similar size. These results therefore suggest that the thermal stability of transmembrane proteins may be governed to a significant extent by cell membrane properties and by interactions between the membrane components and the protein. In contrast, the stability of soluble proteins seems to be mostly governed by protein structure and size, which determine the sum of the stabilizing intramolecular interactions within the protein molecule. It is therefore not surprising that cell membrane properties and composition may have significant effects on the functional properties of transmembrane proteins. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Membrane Biology Springer Journals

Thermal Stability of Dopamine Transporters

Loading next page...
 
/lp/springer_journal/thermal-stability-of-dopamine-transporters-XBt5NYCReV
Publisher
Springer US
Copyright
Copyright © 2015 by Springer Science+Business Media New York
Subject
Life Sciences; Biochemistry, general; Human Physiology
ISSN
0022-2631
eISSN
1432-1424
D.O.I.
10.1007/s00232-015-9794-9
Publisher site
See Article on Publisher Site

Abstract

The thermal stabilities of the rat and mouse dopamine transporter (DAT) proteins were studied within the temperature range of 0–37 °C. The inactivation of the protein was followed by monitoring changes in radioligand-specific binding. We found that the process followed a rate equation with first-order kinetics and was characterized by having a single rate constant k inact. The activation energies (E a) that were calculated from the Arrhenius plots (ln k inact vs. 1/T) were 43 ± 5 and 45 ± 6 kJ/mol for the rat (rDAT) and mouse (mDAT) transporters, respectively, and 44 ± 7 kJ/mol for rDAT from PC-6.3 cell line. These E a values were similar to the E a values of thermal inactivation of the muscarinic receptor from rat brain cortex and to the thermal inactivation of other transmembrane proteins. However, all of these activation energy values were significantly lower than the E a values for soluble single-subunit proteins of similar size. These results therefore suggest that the thermal stability of transmembrane proteins may be governed to a significant extent by cell membrane properties and by interactions between the membrane components and the protein. In contrast, the stability of soluble proteins seems to be mostly governed by protein structure and size, which determine the sum of the stabilizing intramolecular interactions within the protein molecule. It is therefore not surprising that cell membrane properties and composition may have significant effects on the functional properties of transmembrane proteins.

Journal

The Journal of Membrane BiologySpringer Journals

Published: Mar 27, 2015

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off