Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Nagata, Y.
Right arrow Articles by Yamamoto, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nagata, Y.
Right arrow Articles by Yamamoto, T.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

J. Biochem, 1997, Vol. 121, No. 4 648-653
© 1997 Japanese Biochemical Society

research-article

Temperature Sensitivity of Proteoliposomes Reconstituted from a Mixture of Scallop and Rabbit Sarcoplasmic Reticulum Ca2+-ATPases1

Yoshiaki Nagata*, Jun Nakamura{dagger} and Taibo Yamamoto*,2

*Department of Biology, Faculty of Science, Osaka University Toyonaka, Osaka 560
{dagger}Biological Institute, Graduate School of Science, Tohoku University Sendai, Miyagi 980

2To whom correspondence should be addressed.

We reconstituted proteoliposomes by mixing scallop and rabbit sarcoplasmic reticulum, SR, at different protein weight ratios, and investigated the effects of temperature on their Ca2+-transport activity. When proteoliposomes containing scallop and rabbit SR at a protein ratio of 1 : 1 were pre-incubated in the presence of Ca2+ at 39°C for 10 min, the Ca2+-transport activity was almost completely lost, whereas the activity of proteoliposomes containing rabbit SR alone decreased only slightly. Essentially the same results were obtained for proteoliposomes reconstituted with Ca2+-ATPases partially purified from scallop and rabbit SR. The susceptibility of the reconstituted proteoliposomes to heat inactivation increased with an increase in the protein weight ratio of scallop to rabbit SR, the maximum being approached at a ratio higher than 1. When the scallop SR was thermally treated before reconstitution, the resulting vesicles showed as high Ca2+-transport activity as that of control vesicles reconstituted from rabbit SR alone. The former vesicles were not inactivated on further treatment at high temperature. In contrast, when the scallop SR was heated in EGTA before reconstitution of vesicles with rabbit SR, the Ca2+-transport activity of the vesicles was strongly inhibited by subsequent treatment at high temperature in the presence of Ca2+. These results can be easily explained if we assume that Ca2+ transport by the reconstituted vesicles can be catalyzed through a dimeric interaction between the scallop and rabbit Ca2+-ATPases in the membrane. Pre-incubation of these vesicles at 39°C for 10 min in the presence of Ca2+ may destroy the dimeric interaction due to denaturation of the scallop Ca2+-ATPase.

1This study was supported by a Grant-in-Aid from the Ministry of Education, Science, Sports and Culture of Japan, and partially supported by a Grant-in-Aid for Scientific Research on Priority Areas of "Channel-Transporter Correlation."


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Histochem. Cytochem.Home page
H. Plattner, M. Flötenmeyer, R. Kissmehl, N. Pavlovic, K. Hauser, M. Momayezi, N. Braun, J. Tack, and L. Bachmann
Microdomain Arrangement of the SERCA-type Ca2+ Pump (Ca2+-ATPase) in Subplasmalemmal Calcium Stores of Paramecium Cells
J. Histochem. Cytochem., July 1, 1999; 47(7): 841 - 854.
[Abstract] [Full Text]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.