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You searched for +publisher:"University of Alabama – Birmingham" +contributor:("El Khouni, Mahmoud H.<br>"). Showing records 1 – 2 of 2 total matches.

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1. Salman, Emily Deanna. Human cytosolic sulfotransferase 2B1b: structure, function, and expression in human brain.

Degree: PhD, 2011, University of Alabama – Birmingham

The human cytosolic sulfotransferases are a family of phase II drug-metabolizing enzymes that conjugate a sulfonate moiety from 3’-phosphoadenosine 5’-phosphosulfate (PAPS) to a hydroxyl moeity on a substrate. SULT2B1b catalyzes the sulfation of hydroxysteroids as well as many xenobiotics; and is expressed extra-hepatically. SULT2B1b is a unique SULT because it has amino (N)- and carboxy (C)-terminal peptide extensions, undergoes post-translational modification, and is localized in both the cytosol and nucleus. Analysis of SULT2B1b revealed that the N- and C-terminal extensions of SULT2B1b are predicted to be intrinsically unstructured peptides. Size exclusion chromatography has revealed that SULT2B1b is enzymatically active as a homodimer, despite the proximity of the 45 AA C-terminal extension to the dimerization site of SULT2B1b. Nuclear translocation of SULT2B1b appears to be regulated by a PKA-dependent mechanism, because treatment of cells with db-cAMP showed a dose-dependent increase in nuclear translocation of SULT2B1b. Further, site-directed mutagenesis of SULT2B1b showed that Ser348 is associated with nuclear translocation of SULT2B1b. A Ser348 to Asp molecular mimic was generated to evaluate the structural and functional consequences of SULT2B1b phosphorylation. Molecular models of SULT2B1b-S348D showed a 27 Ǻ shift in peptides on the C-terminus of SULT2B1b. Further, recombinant SULT2B1b-S348D showed a 10-fold increase in sulfation activity and increased stability, compared to SULT2B1b. These substantial increases in activity and stability allowed for the determination of KD values for substrates and identification of serveral oxysterols as substrates for SULT2B1b. SULT2B1b mRNA and protein were detected in human brain, whereas neither SULT2A1, nor SULT1E1 were detected. Further, immunoreactive SULT2B1b protein was localized to neurons and oligodendrocytes. SULT2B1b expression and sulfation activity was identified in U-373MG glioblastom cells and SULT2B1b expression in U-373MG cells appears to be regulated by LXR activation. Evaluation of several types of human brain tumors by quantitative RT-PCR and immunoblot analysis demonstrated that SULT2B1b is over-expressed in gliboblastoma and late-state astrocytoma. Because SULT2B1b appears to conjugate neurosteroids, cholesterol, and oxysterols within the brain, understanding the regulatory role of SULT2B1b in the brain will help to elucidate the impact of SULT2B1b involvement in steroid and cholesterol regulation in normal brain and brain tumor physiology.

2011

1 online resource (xx, 296 p. : ill., digital, PDF file)

Pharmacology and Toxicology;

Joint Health Sciences;

Sulfotransferase SULT2B1b neurosteroid nucleus oxysterol brain LXR

UNRESTRICTED

Advisors/Committee Members: Falany, Charles N., El Khouni, Mahmoud H.<br>, Bailey, Shannon M.<br>, Barnes, Stephen<br>, Renfrow, Matthew B.<br>, Wilborn, Teresa W..

Subjects/Keywords: Arylsulfotransferase  – metabolism<; br>; Brain  – enzymology<; br>; Cytosol  – enzymology<; br>; Immunohistochemistry<; br>; Sulfotransferases  – metabolism

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Salman, E. D. (2011). Human cytosolic sulfotransferase 2B1b: structure, function, and expression in human brain. (Doctoral Dissertation). University of Alabama – Birmingham. Retrieved from http://contentdm.mhsl.uab.edu/u?/etd,960

Chicago Manual of Style (16th Edition):

Salman, Emily Deanna. “Human cytosolic sulfotransferase 2B1b: structure, function, and expression in human brain.” 2011. Doctoral Dissertation, University of Alabama – Birmingham. Accessed December 10, 2019. http://contentdm.mhsl.uab.edu/u?/etd,960.

MLA Handbook (7th Edition):

Salman, Emily Deanna. “Human cytosolic sulfotransferase 2B1b: structure, function, and expression in human brain.” 2011. Web. 10 Dec 2019.

Vancouver:

Salman ED. Human cytosolic sulfotransferase 2B1b: structure, function, and expression in human brain. [Internet] [Doctoral dissertation]. University of Alabama – Birmingham; 2011. [cited 2019 Dec 10]. Available from: http://contentdm.mhsl.uab.edu/u?/etd,960.

Council of Science Editors:

Salman ED. Human cytosolic sulfotransferase 2B1b: structure, function, and expression in human brain. [Doctoral Dissertation]. University of Alabama – Birmingham; 2011. Available from: http://contentdm.mhsl.uab.edu/u?/etd,960

2. Buckoreelall, Kajal. Identification and characterization of novel adenosine cleavage enzymes in mycobacteria.

Degree: PhD, 2011, University of Alabama – Birmingham

Tuberculosis (TB) is one of the leading infectious diseases in the world. An estimated one third of the world’s population is infected with Mycobacterium tuberculosis, the causative pathogen of TB. With the emergence of drug resistant strains of the mycobacterium, and the HIV-TB coinfection epidemic, TB remains a global health emergency. Purine metabolism is an essential cellular component to all living cells. Previous studies have shown that differences exist between mycobacterial and human purine metabolism. One of the differences was in the metabolism of adenosine (Ado), whose cleavage was observed in mycobacterial cells whereas Ado cleavage is inefficient in human cells. While Ado cleavage activity had been observed in mycobacteria, the enzyme(s) responsible for this activity was unknown. The identification and understanding of the biochemical properties of Ado cleavage enzyme(s) could aid in the development of Ado analogs for the treatment of TB. There are several candidate enzymes in nature that can cleave Ado, and therefore the identification of endogenous Ado cleavage activity from M. smegmatis was preferred over a genetic approach. This strategy enabled the discovery of two Ado cleavage activities. The first enzyme was named adenosine-purine nucleoside phosphorylase (Ado-PNP), and could cleave Ado, inosine, and guanosine. Because of its ability to cleave Ado, Ado-PNP is different from the trimeric mycobacterial PNP that accepts 6-oxopurines but not 6-aminopurines as substrates. The second enzyme identified could cleave Ado, but 5’-methylthioadenosine (MTA) was the preferred substrate. MTA cleavage was phosphate dependent, and therefore the second Ado-cleaving enzyme identified in M. smegmatis was an MTA phosphorylase. This marked the identification of the first bacterial MTAP. Based on sequence homology, Rv0535 had been annotated as a probable MTAP in M. tuberculosis. Recombinant Rv0535 was expressed, purified, and characterized. While MTA was the preferred substrate, Rv0535 could also cleave Ado and S-adenosyl-L-homocysteine at 2% and 0.8% of the MTA cleavage activity, respectively. To identify other substrates of Rv0535, a structure-activity relationship study was conducted and the initial results are presented. This work has identified two mycobacterial Ado cleavage enzymes that could be exploited for the development of new anti-TB drugs.

1 online resource (xiv, 140 p.) : ill., digital, PDF file.

Pharmacology and Toxicology;

Joint Health Sciences;

Mycobacterium tuberculosis Mycobacterium smegmatis purine metabolism adenosine 5’-methylthioadenosine phosphorylase Rv0535

UNRESTRICTED

Advisors/Committee Members: Parker, William B., King, Jennifer R.<br>, El Khouni, Mahmoud H.<br>, Niederweis, Michael E.<br>, Steyn, Andries J. C..

Subjects/Keywords: Bacterial Proteins  – chemistry<; br>; Bacterial Proteins  – metabolism<; br>; Mycobacterium smegmatis  – enzymology<; br>; Mycobacterium tuberculosis  – enzymology<; br>; Purine-Nucleoside Phosphorylase  – chemistry<; br>; Purine-Nucleoside Phosphorylase  – metabolism

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Buckoreelall, K. (2011). Identification and characterization of novel adenosine cleavage enzymes in mycobacteria. (Doctoral Dissertation). University of Alabama – Birmingham. Retrieved from http://contentdm.mhsl.uab.edu/u?/etd,1136

Chicago Manual of Style (16th Edition):

Buckoreelall, Kajal. “Identification and characterization of novel adenosine cleavage enzymes in mycobacteria.” 2011. Doctoral Dissertation, University of Alabama – Birmingham. Accessed December 10, 2019. http://contentdm.mhsl.uab.edu/u?/etd,1136.

MLA Handbook (7th Edition):

Buckoreelall, Kajal. “Identification and characterization of novel adenosine cleavage enzymes in mycobacteria.” 2011. Web. 10 Dec 2019.

Vancouver:

Buckoreelall K. Identification and characterization of novel adenosine cleavage enzymes in mycobacteria. [Internet] [Doctoral dissertation]. University of Alabama – Birmingham; 2011. [cited 2019 Dec 10]. Available from: http://contentdm.mhsl.uab.edu/u?/etd,1136.

Council of Science Editors:

Buckoreelall K. Identification and characterization of novel adenosine cleavage enzymes in mycobacteria. [Doctoral Dissertation]. University of Alabama – Birmingham; 2011. Available from: http://contentdm.mhsl.uab.edu/u?/etd,1136

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