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Technical Briefs |
1
A/C Diagnostics, LLC, and AntiCancer, Inc., 7917 Ostrow St., San Diego, CA 92111
a author
for correspondence: fax 858-268-4175, e-mail all@anticancer.com
McCully (1) in 1969 first observed that plasma hyperhomocysteinemia was involved in the pathogenesis of arteriosclerosis. More studies have reported that total serum or plasma homocysteine (tHCY) is an independent risk factor for cardiovascular diseases, including arteriosclerosis, coronary artery disease, cerebrovascular disease, and myocardial infarction (2)(3)(4)(5)(6)(7). Furthermore, plasma tHCY is a strong predictor of mortality in patients with existing coronary artery disease (8).
A major basis for hyperhomocysteinemia is insufficient intake of
vitamins B6, B12, and folic
acid, which are necessary for homocysteine metabolism and which lower
the risk for homocysteine-associated diseases (9)(10)(11).
Homocystinuria can result from inborn errors, such as
deficiencies in the enzymes cystathionine ß-synthase,
methionine synthase, and methylenetetrahydrofolate reductase
(12). These patients have premature vascular disease,
50% of untreated patients have thromboembolic events, and the
mortality rate is 20% before the age of 30 (12).
Many methods have been developed to measure tHCY, such as the tHCY enzyme conversion immunoassay designed for the Abbott IMx analyzer (13), the microtiter-plate tHCY enzymatic immunoassay kit (14), and HPLC (15)(16)(17). However, these methods are relatively complex and require highly specialized equipment.
To meet the need for a widely available homocysteine assay, we have
developed and describe here a simple single-enzyme tHCY assay based on
a highly specific homocysteine 
,
-lyase (rHCYase) (18).
L-Homocystine, L-cysteine (L-CYS),
L-methionine (L-MET), dithiothreitol (DTT),
Triton X-100, citric acid, potassium ferricyanide, and other common
reagents for the tHCY enzymatic assay were obtained from Sigma.
4-Fluoro-7-sulfobenzofurazan ammonium salt was obtained from Wako Fine
Chemicals, and N,N-dibutylaniline was obtained from
Acknowledgments
References
The following articles in journals at HighWire Press have cited this article:
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  E.-C. Chan, P.-Y. Chang, T.-L. Wu, and J. T. Wu Enzymatic Assay of Homocysteine on Microtiter Plates or a TECAN Analyzer Using Crude Lysate Containing Recombinant Methionine {gamma}-Lyase Ann. Clin. Lab. Sci., April 1, 2005; 35(2): 155 - 160. [Abstract] [Full Text] [PDF]
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 Q. Han, X. Sun, M. Xu, N. Zhang, L. Tang, Y. Tan, and R. M. Hoffman 3-Deazaadenosine, a Stabilizer of Whole-Blood Homocysteine Content, Does Not Interfere with the Single-Enzyme Homocysteine Assay while Totally Inhibiting the Enzyme Conversion Homocysteine Immunoassay Clin. Chem., September 1, 2004; 50(9): 1703 - 1704. [Full Text] [PDF]
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Q. Han, M. Xu, L. Tang, X. Sun, N. Zhang, X. Tan, X. Tan, Y. Tan, and R. M. Hoffman Homogeneous Enzymatic Colorimetric Assay for Total Cysteine Clin. Chem., July 1, 2004; 50(7): 1229 - 1231. [Full Text] [PDF]
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Y. Tan, X. Sun, L. Tang, N. Zhang, Q. Han, M. Xu, X. Tan, X. Tan, and R. M. Hoffman Automated Enzymatic Assay for Homocysteine Clin. Chem., June 1, 2003; 49(6): 1029 - 1030. [Full Text] [PDF]
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Q. Han, M. Xu, L. Tang, X. Tan, X. Tan, Y. Tan, and R. M. Hoffman Homogeneous, Nonradioactive, Enzymatic Assay for Plasma Pyridoxal 5-Phosphate Clin. Chem., September 1, 2002; 48(9): 1560 - 1564. [Abstract] [Full Text] [PDF]
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N. Matsuyama, M. Yamaguchi, M. Toyosato, M. Takayama, and K. Mizuno New Enzymatic Colorimetric Assay for Total Homocysteine Clin. Chem., December 1, 2001; 47(12): 2155 - 2156. [Full Text] [PDF]
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