Noninvasive imaging of protein metabolic labeling in single human cells using stable isotopes and Raman microscopy

TY - JOUR

T1 - Noninvasive imaging of protein metabolic labeling in single human cells using stable isotopes and Raman microscopy

AU - van Manen, H.J.

AU - Lenferink, Aufrid T.M.

AU - Otto, Cornelis

PY - 2008

Y1 - 2008

N2 - We have combined nonresonant Raman microspectroscopy and spectral imaging with stable isotope labeling by amino acids in cell culture (SILAC) to selectively detect the incorporation of deuterium-labeled phenylalanine, tyrosine, and methionine into proteins in intact, single HeLa cells. The C−D stretching vibrational bands in these amino acids are observed in the 2100−2300 cm−1 spectral region that is devoid of vibrational contributions from other, nondeuterated intracellular constituents. We found that incubation with deuterated amino acids for 8 h in cell culture already led to clearly detectable isotope-related signals in Raman spectra of HeLa cells. As expected, the level of isotope incorporation into proteins increased with incubation time, reaching 55% for deuterated phenylalanine after 28 h. Raman spectral imaging of HeLa cells incubated with deuterium-labeled amino acids showed similar spatial distributions for both isotope-labeled and unlabeled proteins, as evidenced by Raman ratio imaging. The SILAC−Raman methodology presented here combines the strengths of stable isotopic labeling of cells with the nondestructive and quantitative nature of Raman chemical imaging and is likely to become a powerful tool in both cell biology applications and research on tissues or whole organisms

AB - We have combined nonresonant Raman microspectroscopy and spectral imaging with stable isotope labeling by amino acids in cell culture (SILAC) to selectively detect the incorporation of deuterium-labeled phenylalanine, tyrosine, and methionine into proteins in intact, single HeLa cells. The C−D stretching vibrational bands in these amino acids are observed in the 2100−2300 cm−1 spectral region that is devoid of vibrational contributions from other, nondeuterated intracellular constituents. We found that incubation with deuterated amino acids for 8 h in cell culture already led to clearly detectable isotope-related signals in Raman spectra of HeLa cells. As expected, the level of isotope incorporation into proteins increased with incubation time, reaching 55% for deuterated phenylalanine after 28 h. Raman spectral imaging of HeLa cells incubated with deuterium-labeled amino acids showed similar spatial distributions for both isotope-labeled and unlabeled proteins, as evidenced by Raman ratio imaging. The SILAC−Raman methodology presented here combines the strengths of stable isotopic labeling of cells with the nondestructive and quantitative nature of Raman chemical imaging and is likely to become a powerful tool in both cell biology applications and research on tissues or whole organisms

KW - METIS-254098

KW - IR-75806

U2 - 10.1021/ac801841y

DO - 10.1021/ac801841y

M3 - Article

VL - 80

SP - 9576

EP - 9582

JO - Analytical chemistry

JF - Analytical chemistry

SN - 0003-2700

IS - 24

ER -