Novel immunoassays to detect methionine adenosyltransferase activity and quantify S-adenosylmethionine.
We present a novel real-time immunoassay to measure methionine adenosyltransferase (MAT) activity that integrates the MAT-catalyzed reaction of Met and adenosine triphosphate to produce S-adenosylmethionine (SAM) and a highly sensitive immunoassay to specifically quantify SAM simultaneously. The cellular localization of SAM and S-adenosylhomocysteine varies with cell proliferation status: in normal cells, they are found mostly in the cytoplasm, but localize to the nucleus in proliferating cells. MAT-I/III activity is stimulated by Met, but inhibited by S-nitrosoglutathione, and the methylation index (MI) increases after Met stimulation of L02 cells. Met and S-nitrosoglutathione inhibit MAT-II activity, and the MI decreases after Met stimulation of HepG2 cells. The method described provides a significant advancement in the field for the measurement of MAT activity under various conditions.
Arthus Biosystems, Richmond, CA, USA.
Xiujuan
0000-0002-2623-5903
X
Hao
Hunan SkyWorld Biotechnologies Co. Ltd., Hunan, China.
Min
M
Zhou
Hunan SkyWorld Biotechnologies Co. Ltd., Hunan, China.
Huijun
H
Li
Arthus Biosystems, Richmond, CA, USA.
Isaac A
IA
Angres
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000918:Antibody Specificity; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003593:Cytoplasm / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008716:Methionine Adenosyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008745:Methylation / Q000187:drug effects; D051379:Mice; D008856:Microscopy, Fluorescence; D012435:S-Adenosylhomocysteine / Q000378:metabolism*; D012436:S-Adenosylmethionine / Q000378:metabolism*
D004791:Enzyme Inhibitors; D012436:S-Adenosylmethionine; D012435:S-Adenosylhomocysteine; D008716:Methionine Adenosyltransferase
S-adenosylmethionine; carcinogenesis; hepatocellular carcinoma; immunoassay; methionine adenosyltransferase; methylation index