title: Detection of metalloproteins in human liver cytosol by synchrotron radiation X-ray fluorescence combined with gel filtration chromatography and isoelectric focusing separation.
abstract: Synchrotron radiation X-ray fluorescence (SRXRF) spectroscopy is an advanced method of quantitative multielemental analysis with space resolution of several microm and sensitivities in the microg g(-1) range. It can be used for keeping track of trace elements after an electrophoretic separation of biological samples. In this paper, proteins in human liver cytosol were separated with gel filtration chromatography and thin layer isoelectric focusing (IEF). The contents of metal ions in protein bands were determined by SRXRF. The results showed that in the molecular weight (MW) range of 10 approximately 25 kDa, there were at least 2 Zn-containing bands with isoelectric point (pI) of 5 approximately 6 and 6.2 approximately 7, respectively and about 11 Fe-containing proteins with pI of 4.4, 4.6, 4.8, 5.0, 5.2, 5.3, 5.5, 5.6, 6.6, 6.8, and 7.2, respectively, present in human liver cytosol. The Zn-containing band with pI of 5-6 is the dominant species of zinc in this MW range. In addition, the Cu-containing bands with pI of 5.0 and below 4.8 were also detected. It is demonstrated that the procedure could be widely used in further investigations of the chemical species of trace elements in biological samples.
authors.affiliation: Institute of High Energy Physics and Laboratory of Nuclear Analytical Techniques, Chinese Academy of Sciences, PO Box 918, Beijing 100039, P. R. China. gaoyx@ihep.ac.cn
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Gao
authors.forename: Chunying
authors.initials: C
authors.lastname: Chen
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Chai
authors.forename: Jiujiang
authors.initials: J
authors.lastname: Zhao
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Peiqun
authors.initials: P
authors.lastname: Zhang
authors.forename: a Wei
authors.initials: aW
authors.lastname: Heb
authors.forename: Yuying
authors.initials: Y
authors.lastname: Huang
mesh_terms: D002850:Chromatography, Gel / Q000379:methods; D003300:Copper / Q000032:analysis; D003600:Cytosol / Q000737:chemistry; D006801:Humans; D007501:Iron / Q000032:analysis; D007525:Isoelectric Focusing / Q000379:methods; D008099:Liver / Q000737:chemistry*; D008667:Metalloproteins / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods; D017356:Synchrotrons; D015032:Zinc / Q000032:analysis
chemical_list: D008667:Metalloproteins; D003300:Copper; D007501:Iron; D015032:Zinc