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Metabolic Pathway Confirmation and Discovery Through 13C-labeling of Proteinogenic Amino Acids
Published on: January 26, 2012
Methods for measuring sulfur amino acid metabolism
1Lady Davis Institute for Medical Research, Jewish General Hospital, and Department of Medicine, McGill University, Montreal, Quebec, Canada. l.hoffer@mcgill.ca
Current Opinion in Clinical Nutrition and Metabolic Care
|August 13, 2002
Summary
Recent advancements refine sulfur amino acid metabolism studies. New methods improve measurement of homocysteine and related compounds, offering better insights into disease pathogenesis and risk prediction.
Area of Science:
- Biochemistry
- Human Metabolism
- Nutritional Science
Background:
- Sulfur amino acid metabolism is crucial, with methionine and cysteine forming glutathione for antioxidant defense.
- Abnormalities in sulfur amino acid metabolism impact glutathione and homocysteine levels, linked to various diseases.
- Homocysteine, a key sulfur amino acid, is implicated in disease pathogenesis.
Purpose of the Study:
- To review and critique recent developments in human metabolic studies of sulfur amino acids.
- To highlight new methodologies for assessing sulfur amino acid turnover and related compounds.
- To discuss complexities and potential pitfalls in interpreting human metabolic research.
Main Methods:
- Improved Storch-Young model using plasma homocysteine enrichment for methionine turnover.
- New tracer methods (serine, methionine, leucine) to assess folate/pyridoxine effects on methyl transfer.
- Gas chromatography-mass spectrometry for measuring low plasma reduced homocysteine concentrations.
- Fluorescence high-performance liquid chromatography for measuring plasma S-adenosylhomocysteine.
Main Results:
- Enhanced accuracy in determining methionine turnover and homocysteine remethylation.
- Insights into folate and pyridoxine deficiency impacts on human sulfur amino acid metabolism.
- New perspectives on the etiology of hyperhomocysteinemia in chronic renal failure.
- Development of sensitive methods for quantifying homocysteine subspecies and S-adenosylhomocysteine.
Conclusions:
- Recent advancements offer improved tools for studying sulfur amino acid metabolism.
- Plasma S-adenosylhomocysteine may be a superior vascular disease risk predictor compared to homocysteine.
- Careful study design and interpretation are essential for human metabolic research in this field.
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