title: Detection of the recombinant proteins in single transgenic microbial cell using laser tweezers and Raman spectroscopy.
abstract: Laser tweezers Raman spectroscopy (LTRS) has been used for the rapid detection of recombinant somatolactin protein produced in single Escherichia coli bacteria and Pichia pastoris yeast cell in the current study. A cDNA sequence encoding mature peptide of zebrafish somatolactin beta was inserted into two different expression vectors and transfected into E. coli or P. pastoris yeast cells. We measured Raman spectra of single E. coli cells at different culture times following the induction with isopropyl beta-d-1-thiogalactopyranoside, from which the amount of the generated somatolactin proteins was obtained by the projection of the entire cell's spectrum onto the spectrum of the pure somatolactin proteins or the dot product between these two spectral vectors. We found that the intensity of the somatolactin beta protein-associated spectra from single E. coli cells increased as the function of the culture time, which correlates with the accumulation of recombinant proteins inside the cells. This spectral observation was supported by evidence obtained by conventional methods of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting analyses. The increased intensities of recombinant protein-associated Raman bands were also observed in another expression system, P. pastoris yeast cells. These findings demonstrate that the LTRS is a useful method for rapid sensing of recombination production in single host microorganism in vivo.
authors.affiliation: Department of Physics, East Carolina University, Greenville, North Carolina 27858, USA.
authors.forename: Changan
authors.initials: C
authors.lastname: Xie
authors.forename: Nhu
authors.initials: N
authors.lastname: Nguyen
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhu
authors.forename: Yong-qing
authors.initials: YQ
authors.lastname: Li
mesh_terms: D000818:Animals; D004926:Escherichia coli; D029941:Fish Proteins / Q000032:analysis; D006023:Glycoproteins / Q000032:analysis; D052898:Optical Tweezers; D010843:Pichia; D010907:Pituitary Hormones / Q000032:analysis; D011994:Recombinant Proteins / Q000032:analysis*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D015027:Zebrafish
chemical_list: D029941:Fish Proteins; D006023:Glycoproteins; D010907:Pituitary Hormones; D011994:Recombinant Proteins; C064448:somatolactin protein, fish