The long-range objective of this project is to develop methods to modulate peptide hormone action through the peptidases that inactivate them. The focus of this application is to understand the contribution of three metallopeptidases, insulysin, neprilysin, neprilysin-2, and a novel plasma membrane (3-endorphin cleaving enzyme, to neuropeptide metabolism. The three specific aims are: 1. To study the allosteric properties of insulysin and its contribution to modulating physiological peptide levels. Insulysin, which hydrolyzes a variety of peptides including (3-endorphin, insulin, and amyloid (3 peptides is allosterically regulated by both substrates (homotrophic effects) and by anions such as ATP (heterotrophic effects). The heterotrophic effectors switch the preference of the enzyme from cleaving relative large peptides like insulin, amyloid (3-peptide, and -3-endorphin to smaller peptides such as the dynorphins. 2. To study the contribution gate the relative contributions of neprilysin and neprilysin-2 to neuropeptide metabolism in the brain. 3. To isolate and characterize a newly found plasma membrane peptidase that degrades (3-endorphin. We propose to characterize this novel peptidase, determine its tissue distribution as well as its substrate specificity. Relevence: Together these studies should contribute to our understanding of the involvement of a group of peptidases in the regulation of peptide action and may lead to new ways in which to modulate these activities in pathological states. For example one of the peptidases to be studied has recently been implicated in HIV dependent dementia in elderly affected individuals.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA002243-33
Application #
7835549
Study Section
Molecular Neuropharmacology and Signaling Study Section (MNPS)
Program Officer
Purohit, Vishnudutt
Project Start
1978-09-30
Project End
2012-04-30
Budget Start
2010-05-01
Budget End
2011-04-30
Support Year
33
Fiscal Year
2010
Total Cost
$284,625
Indirect Cost
Name
University of Kentucky
Department
Biochemistry
Type
Schools of Medicine
DUNS #
939017877
City
Lexington
State
KY
Country
United States
Zip Code
40506
Song, Eun Suk; Ozbil, Mehmet; Zhang, Tingting et al. (2015) An Extended Polyanion Activation Surface in Insulin Degrading Enzyme. PLoS One 10:e0133114
Guan, Hanjun; Chow, K Martin; Song, Eunsuk et al. (2015) The Mitochondrial Peptidase Pitrilysin Degrades Islet Amyloid Polypeptide in Beta-Cells. PLoS One 10:e0133263
Sexton, Travis; Hitchcook, Lisa J; Rodgers, David W et al. (2012) Active site mutations change the cleavage specificity of neprilysin. PLoS One 7:e32343
Guan, H; Chow, K M; Shah, R et al. (2012) Degradation of islet amyloid polypeptide by neprilysin. Diabetologia 55:2989-98
Noinaj, Nicholas; Song, Eun Suk; Bhasin, Sonia et al. (2012) Anion activation site of insulin-degrading enzyme. J Biol Chem 287:48-57
Song, Eun Suk; Melikishvili, Manana; Fried, Michael G et al. (2012) Cysteine 904 is required for maximal insulin degrading enzyme activity and polyanion activation. PLoS One 7:e46790
Song, Eun Suk; Rodgers, David W; Hersh, Louis B (2011) Mixed dimers of insulin-degrading enzyme reveal a cis activation mechanism. J Biol Chem 286:13852-8
Chirra, Hariharasudhan D; Sexton, Travis; Biswal, Dipti et al. (2011) Catalase-coupled gold nanoparticles: comparison between the carbodiimide and biotin-streptavidin methods. Acta Biomater 7:2865-72
Noinaj, Nicholas; Bhasin, Sonia K; Song, Eun Suk et al. (2011) Identification of the allosteric regulatory site of insulysin. PLoS One 6:e20864
Shen, Xin-Ming; Crawford, Thomas O; Brengman, Joan et al. (2011) Functional consequences and structural interpretation of mutations of human choline acetyltransferase. Hum Mutat 32:1259-67

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