Alternatively Spliced Methionine Synthase in SH-SY5Y Neuroblastoma Cells: Cobalamin and GSH Dependence and Inhibitory Effects of Neurotoxic Metals and Thimerosal

Figure 5

Thimerosal inhibition of MS activity in SH-SY5Y cells. (a) Concentration-dependent inhibition of MeCbl and OHCbl-based MS activity by thimerosal. (b) Thimerosal treatment (10 nM; 1 hr) completely inhibits methylfolate-dependent MS activity in the presence of OHCbl but only partially inhibits activity in the presence of MeCbl. (c) The thimerosal-induced loss of OHCbl-dependent MS activity is reversed by addition of GSH. (d) Cbl levels after thimerosal pretreatment (100 nM) for 4 or 24 hrs. and versus untreated group.

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