Conformational changes in membrane proteins of multidrug-resistant K562 and primary rat hepatocyte cultures as studied by Fourier transform infrared spectroscopy.
The multidrug resistance (MDR) phenotype has been investigated by means of Fourier transform infrared spectroscopy (FT-IR/S) on cell smears. We investigated K562 cell lines (sensitive and doxorubicin-resistant, the latter being MDR too) and primary cultures of rat hepatocytes (HEP). HEP displayed elevated levels of P-glycoprotein (P-gp) with time in 2-4 day-old culture, thus developing in the same time a MDR phenotype. No functional P-gp activity could be detected in HEP at day 1 after cell seeding. Given the sensitivity of FT-IR/S and using computational treatment of FT-IR data, we found that spectra of MDR-K562 and HEP from day 2 to day 4 displayed close protein conformational changes involving beta-sheets. These changes might be in close relationship with the MDR-phenotype and P-gp overexpression.
Laboratoire de Spectroscopie Biomoleculaire, UFR de Pharmacie, Reims, France.
J M
JM
Le Gal
H
H
Morjani
O
O
Fardel
A
A
Guillouzo
M
M
Manfait
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000737:chemistry*; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D004317:Doxorubicin / Q000633:toxicity; D018432:Drug Resistance, Multiple / Q000502:physiology*; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute; D008099:Liver / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D051381:Rats; D017207:Rats, Sprague-Dawley; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014407:Tumor Cells, Cultured
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008565:Membrane Proteins; D004317:Doxorubicin