Determination of δ13C values of valine in protein hydrolysate by gas chromatography–combustion isotope ratio mass spectrometry

Kulik, Wim; Meesterburrie, J.A.N.; Jakobs, Cornelis; Meer, K. de

doi:10.1016/s0378-4347(98)00090-5

Cited by 15 publications

(3 citation statements)

References 20 publications

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“…In principle, abundance data as accurate as that obtained in MS measurement of drug metabolites with internal standards (coefficients of variation Ͻ1%) should ultimately be obtainable. In the early 1980s 18 O-labeled enkephalins were prepared and used to measure these peptides in tissues at ppb levels (75), and in the 1990s GC/MS methods were developed to precisely quantitate stable isotope-labeled amino acids, and hence protein turnover, in human muscle (76,77) and plasma (78,79) proteins labeled in vivo. The extreme sensitivity and precision of these methods suggested that stable isotope approaches could be applied in quantitative proteomics investigations given suitable protein or peptide labeling schemes.…”

Section: Mass Spectrometrymentioning

confidence: 99%

The Human Plasma Proteome

Anderson¹,

Anderson²

2002

Molecular & Cellular Proteomics

3,888

1,585

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The human plasma proteome holds the promise of a revolution in disease diagnosis and therapeutic monitoring provided that major challenges in proteomics and related disciplines can be addressed. Plasma is not only the primary clinical specimen but also represents the largest and deepest version of the human proteome present in any sample: in addition to the classical "plasma proteins," it contains all tissue proteins (as leakage markers) plus very numerous distinct immunoglobulin sequences, and it has an extraordinary dynamic range in that more than 10 orders of magnitude in concentration separate albumin and the rarest proteins now measured clinically. Although the restricted dynamic range of conventional proteomic technology (two-dimensional gels and mass spectrometry) has limited its contribution to the list of 289 proteins (tabulated here) that have been reported in plasma to date, very recent advances in multidimensional survey techniques promise at least double this number in the near future. Abundant scientific evidence, from proteomics and other disciplines, suggests that among these are proteins whose abundances and structures change in ways indicative of many, if not most, human diseases. Nevertheless, only a handful of proteins are currently used in routine clinical diagnosis, and the rate of introduction of new protein tests approved by the United States Food and Drug Administration (FDA) has paradoxically declined over the last decade to less than one new protein diagnostic marker per year. We speculate on the reasons behind this large discrepancy between the expectations arising from proteomics and the realities of clinical diagnostics and suggest approaches by which protein-disease associations may be more effectively translated into diagnostic tools in the future.

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Section: Mass Spectrometrymentioning

confidence: 99%

The Human Plasma Proteome

Anderson¹,

Anderson²

2002

Molecular & Cellular Proteomics

3,888

1,585

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“…The purified piglet albumin appeared as a single band, corresponding to both human albumin purified in our laboratory and commercially obtained human albumin (polyacrylamide gel electrophoresis, silver staining; results not shown). In the dried eluate of the albumin hydrolysates, 13 C‐valine enrichments were determined with gas chromatography–combustion isotope ratio mass, as previously described (10). Quantification of plasma albumin was performed as previously described (3).…”

Section: Methodsmentioning

confidence: 99%

A Single Food Bolus Stimulates Albumin Synthesis in Growing Piglets

de Meer,

Smolders,

Meesterburrie

et al. 2000

J. pediatr. gastroenterol. nutr.

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BackgroundA stable isotope tracer method to quantify the synthesis of proteins of hepatic origin in response to feeding is described. The response of albumin synthesis on one mixed meal in a piglet model was investigated and the intragastric and intravenous administration modes of 13C‐valine were compared.MethodsThe fasting and postprandial fractional synthesis rates (FSRs) of albumin in 15 piglets were measured while infusion rates of 13C‐valine were changed in anticipation of the increased appearance of the tracee after a single liquid food bolus (30 mL/kg infant formula). 13C‐valine enrichments in albumin hydrolysates at regular time intervals were determined with gas chromatography–combustion isotope ratio mass spectrometry.ResultsThe intravenous mode (n = 8) showed constant plasma α‐ketoisovalerate tracer‐to‐tracee ratios (coefficient of variation range: 1–8%), and a 27% increase in albumin FSR after the food bolus (mean FSR ± standard error [SE]: fasting 14.4% ± 1.6% vs. postprandial 18.3% ± 2.2% per day;P < 0.005). In the intragastric mode (n = 7), albumin FSR calculated from the mean precursor values increased 32% after feeding (fasting 14.6% ± 1.5% vs. postprandial 19.3% ± 1.6% per day;P = 0.005), despite absence of constant α‐ketoisovalerate enrichment (coefficient of variation range: 15–31%). The FSRs were not significantly different between both infusion modes.ConclusionsA mixed food bolus increases albumin FSR in growing piglets by approximately 30%, irrespective of the tracer administration route. The concept of anticipated precursor steady state is applicable to study changes of hepatic protein synthesis after a single meal. The intragastric mode of tracer administration can be applied as a less invasive method to measure tissue specific protein synthesis in children.

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“…Another useful and frequent application for GC‐C‐IRMS is the measurement of fractional protein synthesis rates via incorporation of labelled amino acids into tissue proteins. Here the isotope enrichment is usually below the sensitivity of GC‐MS …”

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Practical recommendations for the reduction of memory effects in compound‐specific ¹⁵N/¹⁴N‐ratio analysis of enriched amino acids by gas chromatography/combustion/isotope ratio mass spectrometry

Petzke

Metges

2011

Rapid Comm Mass Spectrometry

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Gas chromatography/combustion/isotope ratio mass spectrometry (GC-C-IRMS) is a highly sensitive approach which allows the analysis of the (13)C/(12)C and (15)N/(14)N isotope composition of amino acids in the range of natural abundance or in slightly (13)C- and (15)N-enriched samples. However, the accuracy of measurements remains a permanent challenge. Here we show the effect of the presence of slightly (15)N-enriched compounds in physiological samples on the accuracy and reproducibility of (15)N-abundances of amino acids within or between analytical runs. We spiked several individual amino acids with the respective (15)N-labelled isotopomer and measured the (15)N/(14)N ratios of other amino acids in the same sample or in the following analytical runs. Intra- and inter-run memory effects can be observed in (15)N/(14)N ratios of amino acids. Sample throughput is reduced when cleaning runs using standard mixtures are required to restore initial conditions after runs of samples with (15)N-enriched analytes. Possible reasons for the observed phenomenon and its implications for work in the lower (15)N-enrichment range (<0.5 APE) are discussed and include different aspects of gas chromatography, derivatisation, and hot catalytic metal surface effects. Results need to be interpreted with caution if complex physiological samples contain (15)N-enriched amino acids beyond 500‰ δ(15)N (~0.18 APE).

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Determination of δ13C values of valine in protein hydrolysate by gas chromatography–combustion isotope ratio mass spectrometry

Cited by 15 publications

References 20 publications

The Human Plasma Proteome

The Human Plasma Proteome

A Single Food Bolus Stimulates Albumin Synthesis in Growing Piglets

Practical recommendations for the reduction of memory effects in compound‐specific ¹⁵N/¹⁴N‐ratio analysis of enriched amino acids by gas chromatography/combustion/isotope ratio mass spectrometry

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Determination of δ13C values of valine in protein hydrolysate by gas chromatography–combustion isotope ratio mass spectrometry

Cited by 15 publications

References 20 publications

The Human Plasma Proteome

The Human Plasma Proteome

A Single Food Bolus Stimulates Albumin Synthesis in Growing Piglets

Practical recommendations for the reduction of memory effects in compound‐specific 15N/14N‐ratio analysis of enriched amino acids by gas chromatography/combustion/isotope ratio mass spectrometry

Contact Info

Product

Resources

About

Practical recommendations for the reduction of memory effects in compound‐specific ¹⁵N/¹⁴N‐ratio analysis of enriched amino acids by gas chromatography/combustion/isotope ratio mass spectrometry