Characterization of calmodulin effects on calcium transport in cardiac microsomes enriched in sarcoplasmic reticulum
department or school: Pharmaceutical Sciences, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Lopaschuk, Gary David
issued: 2010-03-19T20:17:29Z
issued: 1980
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Calmodulin prepared from red cell hemolysate stimulates Ca²⁺ -transport in cardiac microsomal preparations enriched in sarcoplasmic reticulum (S.R.) in a concentration-dependent manner (Katz and. Remtulla, 1978). The present study was performed to characterize this calmodulin regulation of Ca²⁺-transport. K⁺ and Na⁺ have also been found to enhance Ca²⁺-transport in microsomal preparations enriched in S.R. (Jones et al, 1978). It was observed that in the presence of K⁺ (110 mM) and Na⁺ (110 mM) stimulation of Ca²⁺-transport activity by calmodulin was greatly reduced. This result was obtained at all free Ca concentrations studied. That this was not an ionic effect was indicated by the decreased antagonism of calmodulin stimulation by Li⁺ (110 mM). Kinetic characterization determined that calmodulin significantly enhanced the maximal Ca²⁺activation without affecting the apparent Ca²⁺affinity of the Ca²⁺-transport process in cardiac S.R.. K⁺ was found to enhance the V[sub Ca²⁺] as well as lowering the apparent Ca²⁺ affinity. Examination of the initial rate of Ca²⁺-transport in cardiac S.R. confirmed that calmodulin stimulation is due mainly to an increase in the V[sub Ca²⁺]. CyclicAMP-dependent protein kinase, on the other hand, has been shown to increase the V[sub Ca²⁺], as well as decrease the apparent K[sub m] for Ca²⁺ (Hicks et al, 1979), suggesting a different mechanism of action. Experiments were performed to investigate whether calmodulin was indigenous to the preparations used. Attempts were therefore made to isolate calmodulin from dog cardiac microsomal preparations enriched in S.R. by methodology used to isolate calmodulin from other sources (Jung, 1978; Depaoli-Roach et al, 1979). These extracts were then tested to determine their ability to stimulate Ca²⁺-transport into S.R.. It was observed that neither boiling nor treatment with 0.6mM EGTA could extract calmodulin from these preparations. This result indicates that the microsomal preparations utilized do …
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/22153
note: CHARACTERIZATION OF CALMODULIN EFFECTS ON CALCIUM TRANSPORT IN CARDIAC MICROSOMES ENRICHED IN SARCOPLASMIC RETICULUM ( ^ ^ ) G A R Y DAVID LOPASCHUK B . S c , The U n i v e r s i t y o f B r i t i s h C o l u m b i a , 1978 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES i n THE FACULTY OF PHARMACEUTICAL SCIENCES D I V I S I O N OF PHARMACOLOGY AND TOXICOLOGY We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE UNIVERSITY OF B R I T I S H COLUMBIA September 19 80 • 0 Gary D a v i d L o p a s c h u k , 1980 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r an a d v a n c e d d e g r e e a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r a g r e e t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by t h e Head o f my D e p a r t m e n t o r by h i s r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . D e p a r t m e n t o f Pharmacology. F a c u l t y of Pharmaceutical Sciences The U n i v e r s i t y o f B r i t i s h C o l u m b i a 2075 Wesbrook P l a c e Vancouver, Canada V6T 1W5 D a t e September 18, 1980 i i ABSTRACT 2+ Calmodulin prepared from red c e l l hemolysate stimulates Ca -transport i n cardiac microsomal preparations enriched i n sarcoplasmic reticulum (S.R.) i n a concentration-dependent manner (Katz and. Remtulla, 1978). The present study was performed to characterize t h i s calmodulin 2+ + + reg…
has type: Thesis/Dissertation
is shown at: 10.14288/1.0100288
language: eng
degree discipline: Pharmaceutical Sciences
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/22153