Masters Theses

Keywords and Phrases



"Muscarinic acetylcholine receptors possess a conserved pair of extracellular cysteines which form a disulfide bond between the 1st and the 2nd extracellular loop. Previous work has shown that the disulfide bond forming cysteines influence ligand binding and receptor interaction with transducer proteins. Nitric oxide (NO) has multiple roles in cellular signaling. One mechanism for NO activity is the nitrosylation of protein sulfhydryl groups. Accordingly, in the present studies the role of the nitric oxide generating compound sodium nitroprusside on ligand binding to muscarinic receptors of rat brainstem was studied. Treatment of rat brainstem membranes with sodium nitroprusside decreased ligand binding to muscarinic receptors by 70-80%. This inhibition was completely dependent on previous reduction of the membranes with dithiothreitol, suggesting that cysteine groups normally participating in disulfide bond formation were involved. This decrease in binding reflected a decrease in receptor concentration, rather than a change in ligand affinity. Moreover, this effect of sodium nitroprusside was eliminated by alkylation of sulfhydryl moieties with N-ethylmaleimide. Unexpectedly this effect was not observed in Chinese hamster ovary cells stably transfected with gene for the M2 muscarinic receptor. Eliminating the cysteines participating in disulfide bond between the 1st and 2nd extracellular loops prevented expression of the receptor in CHO cells as judged by ligand binding and histochemical evidence. These results support the notion that regulation of muscarinic receptor sulfhydryl groups plays a role in the modulation of receptor activity "--Abstract, page iii.


Aronstam, Robert

Committee Member(s)

Ercal, Nuran
Shannon, Katie


Biological Sciences

Degree Name

M.S. in Applied and Environmental Biology


University of Missouri--Rolla

Publication Date

Spring 2007


x, 57 pages

Note about bibliography

Includes bibliographical references (pages 55-56).


© 2007 Pradnya Pandurang Patil, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Cellular signal transduction
G proteins
Muscarinic receptors

Thesis Number

T 9130

Print OCLC #


Link to Catalog Record

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