Sulfur Metabolism and its Clinical Correlations

Objective. My talk would cover overall sulfur metabolism and various clinical correlations of sulfur biology including cancer. Background. Sulfur is one of the chief elements that are required for normal biological functions. From archaea to mammals importance of sulfur has been realized. Sulfur in the form of inorganic anion (sulfate) is specifically transported from extracellular milieu into intracellular regions. Once inside the cell it is reduced into sulfide by complex sets of enzymes. The reduced sulfide is then incorporated into carbon compounds for example in the form of the amino acid, methionine. The sulfate reduction and de novo synthesis of methionine is absent in mammals. Thus methionine is an essential amino acid for mammals that would have to come from diet especially during development and cell divisions. Inorganic sulfate can also be converted to 3’-phosphoadenosine 5’- phosphosulfate (PAPS) using ATP by PAPS synthase in two sequential steps. PAPS is the universal sulfuryl donor. Methods. Enzyme assays of PAPS synthase and Methionase will be discussed. Results. PAPS synthase and Methionase are two key enzymes of sulfur metabolism. Conclusion. There are many small molecules as well as macromolecules that get sulfonated by respective sulfotransferases. Once sulfonated the physico-chemical properties of the recipient compounds is altered. Deficiency in sulfonation can lead to serious diseases like skeletal deformity. Grants. HPD and PFR&D of NSU

Effects of Methionine Gamma Lyase-Deaminase on Human Colorectal Carcinoma Cells

Objective. The objective of this study is to demonstrate the effects of methionine gamma lyase-deaminase (Mgld) on colorectal carcinoma cell survival using MTT assay. Background. Mgld is in enzyme found in bacteria and protozoa including, Porphyromonas gingivalis. Mgld has the ability to catabolize methionine, an enzyme function that is absent in mammals. This enzyme function is of interest in methionine/S-adenosyl methionine (SAM) dependent cancer cells given the dysregulation of DNA methylation patterns that occur compared to normal mammalian cells. Methods. In this study, Porphyromonas gingivalis Mgld cloned into a cytoplasmic and nuclear plasmid vector was transfected into the human colorectal carcinoma T84 cell line using Lipofectamine 3000. The effects of cytoplasmic Mgld and nuclear Mgld were assessed in comparison to control non-transfected cells. Cell survival was assessed with an MTT assay at 570 nm as an indicator of metabolic functions of the live cells/mitochondria. Results. Results indicate that nuclear Mgld transfection causes most significant inhibition of metabolic activity in T84 colorectal carcinoma cells with a 19% decrease in absorbance compared to the control. Conclusion. Due to its effects on cellular survival, further studies should be conducted to evaluate and investigate the metabolic implications of nuclear Mgld on T84 colorectal carcinoma cells