Activation of the Cardiac Ryanodine Receptor by Sulfhydryl Oxidation is Modified by Mg2+ and ATP

Activation of the Cardiac Ryanodine Receptor by Sulfhydryl Oxidation is Modified by Mg2+ and ATP The reactive disulfide 4,4′-dithiodipyridine (4,4′DTDP) was added to single cardiac ryanodine receptors (RyRs) in lipid bilayers. The activity of native RyRs, with cytoplasmic (cis) [Ca2+] of 10−7 m (in the absence of Mg2+ and ATP), increased within ∼1 min of addition of 1 mm 4,4′-DTDP, and then irreversibly ceased 5 to 6 min after the addition. Channels, inhibited by either 1 mm cis Mg2+ (10−7 m cis Ca2+) or by 10 mm cis Mg2+ (10−3 m cis Ca2+), or activated by 4 mm ATP (10−7 m cis Ca2+), also responded to 1 mm cis 4,4′-DTDP with activation and then loss of activity. P o and mean open time (T o ) of the maximally activated channels were lower in the presence of Mg2+ than in its absence, and the number of openings within the long time constant components of the open time distribution was reduced. In contrast to the reduced activation by 1 mm 4,4′-DTDP in channels inhibited by Mg2+, and the previously reported enhanced activation by 4,4′-DTDP in channels activated by Ca2+ or caffeine (Eager et al., 1997), the activation produced by 1 mm cis 4,4′-DTDP was the same in the presence and absence of ATP. These results suggest that there is a physical interaction between the ATP binding domain of the cardiac RyR and the SH groups whose oxidation leads to channel activation. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Membrane Biology Springer Journals

Activation of the Cardiac Ryanodine Receptor by Sulfhydryl Oxidation is Modified by Mg2+ and ATP

Loading next page...
 
/lp/springer_journal/activation-of-the-cardiac-ryanodine-receptor-by-sulfhydryl-oxidation-Sa9ZWrLdZ7
Publisher
Springer-Verlag
Copyright
Copyright © Inc. by 1998 Springer-Verlag New York
Subject
Life Sciences; Biochemistry, general; Human Physiology
ISSN
0022-2631
eISSN
1432-1424
D.O.I.
10.1007/s002329900365
Publisher site
See Article on Publisher Site

Abstract

The reactive disulfide 4,4′-dithiodipyridine (4,4′DTDP) was added to single cardiac ryanodine receptors (RyRs) in lipid bilayers. The activity of native RyRs, with cytoplasmic (cis) [Ca2+] of 10−7 m (in the absence of Mg2+ and ATP), increased within ∼1 min of addition of 1 mm 4,4′-DTDP, and then irreversibly ceased 5 to 6 min after the addition. Channels, inhibited by either 1 mm cis Mg2+ (10−7 m cis Ca2+) or by 10 mm cis Mg2+ (10−3 m cis Ca2+), or activated by 4 mm ATP (10−7 m cis Ca2+), also responded to 1 mm cis 4,4′-DTDP with activation and then loss of activity. P o and mean open time (T o ) of the maximally activated channels were lower in the presence of Mg2+ than in its absence, and the number of openings within the long time constant components of the open time distribution was reduced. In contrast to the reduced activation by 1 mm 4,4′-DTDP in channels inhibited by Mg2+, and the previously reported enhanced activation by 4,4′-DTDP in channels activated by Ca2+ or caffeine (Eager et al., 1997), the activation produced by 1 mm cis 4,4′-DTDP was the same in the presence and absence of ATP. These results suggest that there is a physical interaction between the ATP binding domain of the cardiac RyR and the SH groups whose oxidation leads to channel activation.

Journal

The Journal of Membrane BiologySpringer Journals

Published: May 1, 1998

There are no references for this article.

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