Mark E. Merchant

221 Kirkman Hall

mmerchan@mail.mcneese.edu

www.faculty.mcneese.edu/mmerchan

337-475-5773

Field of Specialization

Biochemistry

Current Graduate Students

Education and Employment

B. S. Chemistry

Lamar University (1988)

Beaumont, Texas

B. S. Biology

Lamar University (1988)

Beaumont, Texas

Ph. D. Biochemistry

Texas A & M University (1992)

College Station, Texas

Post-Doctoral Fellow

University of Texas Medical Branch (1992-1996)

Galveston, Texas

R & D Laboratory Manager

Helena Laboratories (1996-2001)

Beaumont, Texas

Assistant Professor of Biochemistry

McNeese State University (2002-Present)

Lake Charles, Louisiana

Teaching

CHEM 265, 275, 431, 432, 610

Research

Alligators have been known to sustain serious injuries that heal very rapidly and almost always without infection. The fact that alligators eat bacteria-laden carrion and sometimes live in stagnant waters with no ill effects makes them interesting subjects for immunological studies. The focus of our laboratory research efforts is on the antimicrobial properties of alligator blood and other tissues.

PROJECT 1 — Preliminary results in our laboratory have indicated that crude preparations of alligator blood inhibit bacterial growth in a time- and concentration-dependent manner. The antibacterial properties can be obliterated by incubation of serum at 56oC or treatment of serum with proteases, which suggests that the antimicrobial activity may be due to the serum complement system of proteins that is responsible for modulation of immune function. We are the first group to report the presence of a serum complement system in alligators.

PROJECT 2 — Multicellular organisms must continuously defend against penetration and colonization by potentially infectious microbes. The initial host resistance mechanisms do not include antibody-mediated processes that often take days to develop, but are facilitated by the innate immune system which includes, but is not limited to, the expression of small peptides that exhibit potent antimicrobial activities. These peptides often exhibit broad-spectrum antimicrobial activities and thus provide an initial nonspecific defense mechanism designed to protect against potentially infectious microbes. Our research group is currently working to isolate antimicrobial peptides from the leukocytes of alligators. These antibiotic peptides may have use in modern medicine to treat antibiotic-resistant infections. Future studies will be focused on isolation of the gene which encodes these peptides. The antibiotic peptide genes can be transferred to disease-susceptible plants to create transgenic disease-resistant crops.

PROJECT 3 — Complement protein C3 is an important molecule for the modulation of immune function for both the alternative and classical pathways. Recent studies in our laboratory have shown that antibodies directed toward human C3 complement are capable of cross-reacting with alligator C3 protein. This is interesting considering that alligators evolved approximately 150 million years before the appearance of hominids. In addition, the conservation of this protein exhibits the extreme importance of its purpose in modulation of immune and inflammatory function. We will use the antibodies directed toward human C3 to isolate alligator C3 protein. The protein will be characterized and used to study alligator immune function.

Publications

Merchant, M., Keherley, M., Miflin, R., and Papaconstantinou, J. (1997). Cloning and promoter activity of the murine a1-acid glycoprotein gene. Genomics 23 (1), 316-322.

Merchant, M., and Papaconstantinou, J. (1995). Induction of a1-acid glycoprotein gene expression by heavy metals. Toxic Subst. J. 46 (1), 362-366.

Merchant, M., Yiangou, M., and Papaconstantinou, J. (1994). Transcriptional regulation of a1-acid glycoprotein gene expression by mercury. Toxic Subst. J. 45 (3), 127-131.

Merchant, M. and Safe, S. (1995). In vitro inhibition of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced activity by a-naphthoflavone and 6-methyl-1,3,8-trichlorodibenzofuran using an aryl-hydrocarbon (Ah)-responsive construct. Biochem. Pharmacol. 50 (5), 663-668.

Weber, T., Ou, X., Merchant, M., Wang, X., Safe, S., and Ramos, K. (1994). Biphasic modulation of protein kinase C (PKC) activity by polychlorinated dibenzo-p-dioxins (PCDDs) in serum-deprived rat aortic smooth muscle cells. J. Biochem. Toxicol. 9 (3), 113-120.

Sadhu, D., Merchant, M., and Ramos, K. (1993). Modulation of protooncogene expression in rat aortic smooth muscle cells by benzo(a)pyrene. Arch. Biochem. Biophys. 300, 124-131.

Santostefano, M., Merchant, M., Arellano, L, Morrison, V., Denison, M., and Safe, S. (1993). a-Naphthoflavone-induced CYPIA1 gene expression and cytosolic aryl hydrocarbon receptor transformation. Mol. Pharmacol. 43 (2), 200-206.

Merchant, M., Krishnan, V., and Safe, S. (1993). Mechanism of action a-naphthoflavone as an aryl hydrocarbon receptor antagonist in MCF-7 human breast cancer cells. Toxicol. Appl. Pharmacol. 120 (2), 19-185.

Merchant, M., Morrison, V., and Safe, S. (1992). Antagonsim of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced CYPIA1 gene expression by 6-methyl-1,3,8-trichlorodibenzofuran: mechanistic studies. Chemosphere 25 (7-10), 963-973.

Merchant, M., Santostefano, M., Krishnan, V., and Safe, S. (1992). In vitro bioassays for polychlorinated diphenyl ethers: quantitative structure-activity relationships. Organohalogen Compounds 10, 331-334.

Merchant, M., Santostefano, M., Morrison, V., and Safe, S. (1992). Mechanism of actionof 2,3,7,8-tetrachlorobibenzo-p-dioxin antagonists: inhibition of induction of CYPIA1 gene expression. Arch. Biochm. Biophys. 298 (2), 389-394.

Zacharewski, T., Harris, M., Biegel, L., Morrison, V., and Safe, S. (1992). 6-Methyl-1,3,8-trichlorodibenzofuran (MCDF) as an antiestrogen in human and rodent cell lines: evidence for the role of the Ah receptor. Toxicol. Appl. Pharamcol. 113, 311-318.

Merchant, M., Wang, X., Rosengren, R., Morrison, V., Kamps, C., and Safe, S. (1992). Mechanism of benzo(a)pyrene-induced CYP1a-1 gene expression in hep 1c1c7 cells: role of the nuclear 4S and 6S proteins. Arch. Biochem. Biophys. 281 (1), 84-89.

Mechant, M., Shukla, S., and Akers, H. (1991). Lead concentrations in the wing bones of the mottled duck. Environ. Toxicol. Chem., 1503-1507.

Merchant, M., Arellano, L., and Safe, S. (1990). The mechanism of action of a-naphthoflavone as an inhibitor of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced CYPIA1 gene expression. Arch. Biochem. Biophys. 292 (1). 250-257.

Merchant, M., Narashiman, T., and Safe, S. (1990). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) as a monooxygenase inducer in human cell lines: comparative effects of different antagonists. Proc. 10th Int. Meeting in Dioxin 1, 117-120.

Merchant, M., Arellano, L., and Safe, S. (1990). a-naphthoflavone and 1-amino-3,7,8-trichloro-p-dioxin as 2,3,7,8-TCDD antagonists in rat hepatoma H-4-IIE cells. Proc. 10th Int. Meeting in Dioxin 1, 111-115.

Grants and Awards

Kirkman Hall Ron W. Darbeau Mark S. Delaney Mark E. Merchant Jesse R. Ortego Gerald J. Ramelow Ulku S. Ramelow Christopher F. Rodriquez Carol E. Schulte Joan E. Vallee Danette Vines Faculty Home Page
	Mark E. Merchant 221 Kirkman Hall mmerchan@mail.mcneese.edu www.faculty.mcneese.edu/mmerchan 337-475-5773 Field of Specialization Biochemistry Current Graduate Students Education and Employment B. S. Chemistry Lamar University (1988) Beaumont, Texas B. S. Biology Lamar University (1988) Beaumont, Texas Ph. D. Biochemistry Texas A & M University (1992) College Station, Texas Post-Doctoral Fellow University of Texas Medical Branch (1992-1996) Galveston, Texas R & D Laboratory Manager Helena Laboratories (1996-2001) Beaumont, Texas Assistant Professor of Biochemistry McNeese State University (2002-Present) Lake Charles, Louisiana Teaching CHEM 265, 275, 431, 432, 610 Research Alligators have been known to sustain serious injuries that heal very rapidly and almost always without infection. The fact that alligators eat bacteria-laden carrion and sometimes live in stagnant waters with no ill effects makes them interesting subjects for immunological studies. The focus of our laboratory research efforts is on the antimicrobial properties of alligator blood and other tissues. PROJECT 1 — Preliminary results in our laboratory have indicated that crude preparations of alligator blood inhibit bacterial growth in a time- and concentration-dependent manner. The antibacterial properties can be obliterated by incubation of serum at 56oC or treatment of serum with proteases, which suggests that the antimicrobial activity may be due to the serum complement system of proteins that is responsible for modulation of immune function. We are the first group to report the presence of a serum complement system in alligators. PROJECT 2 — Multicellular organisms must continuously defend against penetration and colonization by potentially infectious microbes. The initial host resistance mechanisms do not include antibody-mediated processes that often take days to develop, but are facilitated by the innate immune system which includes, but is not limited to, the expression of small peptides that exhibit potent antimicrobial activities. These peptides often exhibit broad-spectrum antimicrobial activities and thus provide an initial nonspecific defense mechanism designed to protect against potentially infectious microbes. Our research group is currently working to isolate antimicrobial peptides from the leukocytes of alligators. These antibiotic peptides may have use in modern medicine to treat antibiotic-resistant infections. Future studies will be focused on isolation of the gene which encodes these peptides. The antibiotic peptide genes can be transferred to disease-susceptible plants to create transgenic disease-resistant crops. PROJECT 3 — Complement protein C3 is an important molecule for the modulation of immune function for both the alternative and classical pathways. Recent studies in our laboratory have shown that antibodies directed toward human C3 complement are capable of cross-reacting with alligator C3 protein. This is interesting considering that alligators evolved approximately 150 million years before the appearance of hominids. In addition, the conservation of this protein exhibits the extreme importance of its purpose in modulation of immune and inflammatory function. We will use the antibodies directed toward human C3 to isolate alligator C3 protein. The protein will be characterized and used to study alligator immune function. Publications Merchant, M., Keherley, M., Miflin, R., and Papaconstantinou, J. (1997). Cloning and promoter activity of the murine a1-acid glycoprotein gene. Genomics 23 (1), 316-322. Merchant, M., and Papaconstantinou, J. (1995). Induction of a1-acid glycoprotein gene expression by heavy metals. Toxic Subst. J. 46 (1), 362-366. Merchant, M., Yiangou, M., and Papaconstantinou, J. (1994). Transcriptional regulation of a1-acid glycoprotein gene expression by mercury. Toxic Subst. J. 45 (3), 127-131. Merchant, M. and Safe, S. (1995). In vitro inhibition of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced activity by a-naphthoflavone and 6-methyl-1,3,8-trichlorodibenzofuran using an aryl-hydrocarbon (Ah)-responsive construct. Biochem. Pharmacol. 50 (5), 663-668. Weber, T., Ou, X., Merchant, M., Wang, X., Safe, S., and Ramos, K. (1994). Biphasic modulation of protein kinase C (PKC) activity by polychlorinated dibenzo-p-dioxins (PCDDs) in serum-deprived rat aortic smooth muscle cells. J. Biochem. Toxicol. 9 (3), 113-120. Sadhu, D., Merchant, M., and Ramos, K. (1993). Modulation of protooncogene expression in rat aortic smooth muscle cells by benzo(a)pyrene. Arch. Biochem. Biophys. 300, 124-131. Santostefano, M., Merchant, M., Arellano, L, Morrison, V., Denison, M., and Safe, S. (1993). a-Naphthoflavone-induced CYPIA1 gene expression and cytosolic aryl hydrocarbon receptor transformation. Mol. Pharmacol. 43 (2), 200-206. Merchant, M., Krishnan, V., and Safe, S. (1993). Mechanism of action a-naphthoflavone as an aryl hydrocarbon receptor antagonist in MCF-7 human breast cancer cells. Toxicol. Appl. Pharmacol. 120 (2), 19-185. Merchant, M., Morrison, V., and Safe, S. (1992). Antagonsim of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced CYPIA1 gene expression by 6-methyl-1,3,8-trichlorodibenzofuran: mechanistic studies. Chemosphere 25 (7-10), 963-973. Merchant, M., Santostefano, M., Krishnan, V., and Safe, S. (1992). In vitro bioassays for polychlorinated diphenyl ethers: quantitative structure-activity relationships. Organohalogen Compounds 10, 331-334. Merchant, M., Santostefano, M., Morrison, V., and Safe, S. (1992). Mechanism of actionof 2,3,7,8-tetrachlorobibenzo-p-dioxin antagonists: inhibition of induction of CYPIA1 gene expression. Arch. Biochm. Biophys. 298 (2), 389-394. Zacharewski, T., Harris, M., Biegel, L., Morrison, V., and Safe, S. (1992). 6-Methyl-1,3,8-trichlorodibenzofuran (MCDF) as an antiestrogen in human and rodent cell lines: evidence for the role of the Ah receptor. Toxicol. Appl. Pharamcol. 113, 311-318. Merchant, M., Wang, X., Rosengren, R., Morrison, V., Kamps, C., and Safe, S. (1992). Mechanism of benzo(a)pyrene-induced CYP1a-1 gene expression in hep 1c1c7 cells: role of the nuclear 4S and 6S proteins. Arch. Biochem. Biophys. 281 (1), 84-89. Mechant, M., Shukla, S., and Akers, H. (1991). Lead concentrations in the wing bones of the mottled duck. Environ. Toxicol. Chem., 1503-1507. Merchant, M., Arellano, L., and Safe, S. (1990). The mechanism of action of a-naphthoflavone as an inhibitor of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced CYPIA1 gene expression. Arch. Biochem. Biophys. 292 (1). 250-257. Merchant, M., Narashiman, T., and Safe, S. (1990). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) as a monooxygenase inducer in human cell lines: comparative effects of different antagonists. Proc. 10th Int. Meeting in Dioxin 1, 117-120. Merchant, M., Arellano, L., and Safe, S. (1990). a-naphthoflavone and 1-amino-3,7,8-trichloro-p-dioxin as 2,3,7,8-TCDD antagonists in rat hepatoma H-4-IIE cells. Proc. 10th Int. Meeting in Dioxin 1, 111-115. Grants and Awards
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