Enzymatic decarboxylation of tyrosine and phenylalanine to enhance volatility for high-precision isotopic analysis

被引:10
作者
Ziadeh, BI
Michaud, AL
Saad, NMR
Lewis, BA
Rafii, M
Pencharz, PB
Brenna, JT
机构
[1] Cornell Univ, Div Nutr Sci, Ithaca, NY 14850 USA
[2] Hosp Sick Children, Res Inst, Toronto, ON M5G 1X8, Canada
[3] Univ Toronto, Dept Paediat & Nutr Sci, Toronto, ON M5G 1X8, Canada
关键词
D O I
10.1021/ac015558j
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
We present a rapid and selective method to increase the volatility of tyrosine and phenylalanine without adding derivative C for high-precision gas chromatography-continuous-flow isotope ratio mass spectrometry (GCC-IRMS) based on enzymatic decarboxylation to yield alkyl-amines and evaluated for N-15 isotopic integrity. Purified tyrosine and phenylalanine were converted to tyramine and phenethylamine by tyrosine and phenylalanine decarboxylases, respectively. GC separation was achieved using a thick stationary phase (5-mum) capillary column. Recoveries were 95 +/- 2%. The reproducibility of delta(15)N of tyramine and phenethylamine measured by GCC-IRMS averaged SD(delta(15)N) = 0.33parts per thousand. The absolute differences between delta(15)N of amino acids measured by elemental analyzer-IRMS and the alkylamines measured by GCC-IRMS was not significant. Phenethylamine and tyramine prepared from a mixture of 18 amino acids were extracted by ethanol with 95% recovery, and analysis yielded clean chromatograms and equivalent precision. These data indicate that enzymatic decarboxylation of phenylalanine and tyrosine is a convenient method to increase their volatility for continuous-flow isotopic analysis without introducing extraneous C or significant isotopic fractionation.
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页码:479 / 483
页数:5
相关论文
共 31 条
[1]   STUDIES OF ENZYME-MEDIATED REACTIONS .12. STEREOCHEMICAL COURSE OF THE DECARBOXYLATION OF (2S)-TYROSINE TO TYRAMINE BY MICROBIAL, MAMMALIAN, AND PLANT-SYSTEMS [J].
BATTERSBY, AR ;
CHRYSTAL, EJT ;
STAUNTON, J .
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 1980, (01) :31-42
[2]   CONDENSED-PHASE CARBON ISOTOPIC STANDARDS FOR COMPOUND-SPECIFIC ISOTOPE ANALYSIS [J].
CAIMI, RJ ;
HOUGHTON, LA ;
BRENNA, JT .
ANALYTICAL CHEMISTRY, 1994, 66 (18) :2989-2991
[3]   THE DETERMINATION OF LOW D(5)-PHENYLALANINE ENRICHMENT (0.002-0.09 ATOM PERCENT EXCESS), AFTER CONVERSION TO PHENYLETHYLAMINE, IN RELATION TO PROTEIN-TURNOVER STUDIES BY GAS-CHROMATOGRAPHY ELECTRON IONIZATION MASS-SPECTROMETRY [J].
CALDER, AG ;
ANDERSON, SE ;
GRANT, I ;
MCNURLAN, MA ;
GARLICK, PJ .
RAPID COMMUNICATIONS IN MASS SPECTROMETRY, 1992, 6 (07) :421-424
[4]   PHENYLALANINE AND TYROSINE KINETICS IN CRITICALLY ILL CHILDREN WITH SEPSIS [J].
CASTILLO, L ;
YU, YM ;
MARCHINI, JS ;
CHAPMAN, TE ;
SANCHEZ, M ;
YOUNG, VR ;
BURKE, JF .
PEDIATRIC RESEARCH, 1994, 35 (05) :580-588
[5]  
Dänicke S, 1999, ARCH ANIM NUTR, V52, P41, DOI 10.1080/17450399909386150
[6]  
FULLER MF, 1992, ANNU REV NUTR, V14, P217
[7]   HIGH-SENSITIVITY TRACER DETECTION USING HIGH-PRECISION GAS-CHROMATOGRAPHY COMBUSTION ISOTOPE RATIO MASS-SPECTROMETRY AND HIGHLY ENRICHED [U-C-13]-LABELED PRECURSORS [J].
GOODMAN, KJ ;
BRENNA, JT .
ANALYTICAL CHEMISTRY, 1992, 64 (10) :1088-1095
[8]  
GREMAUD G, 1998, ISOT ENVIRON HEALT S, V34, P148
[9]  
Hofmann D, 1997, J MASS SPECTROM, V32, P855, DOI 10.1002/(SICI)1096-9888(199708)32:8<855::AID-JMS544>3.3.CO
[10]  
2-A