Secondary Structure Alterations of Histones H2A and H2B in X-Irradiated Human Cancer Cells: Altered Histones Persist in Cells for at Least 24 Hours.
We measured and compared the circular dichroism (CD) spectra and secondary structures of histone proteins H2A, H2B and their variants extracted from X-irradiated and unirradiated human HeLa cells. Compared to unirradiated cells, a relative increase in α-helix structure and decrease in other secondary structures was observed in X-irradiated cells. These structural alterations persisted for at least 24 h, which is substantially longer than the 2 h generally known to be required for DNA double-strand break repair.
a  Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Japan.
Yudai
Y
Izumi
b  College of Science, Ibaraki University, Japan.
Satoshi
S
Yamamoto
a  Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Japan.
Kentaro
K
Fujii
a  Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Japan.|c  Graduate School of Science and Engineering, Ibaraki University, Japan.
Akinari
A
Yokoya
D004260:DNA Repair / Q000528:radiation effects; D006367:HeLa Cells; D006657:Histones / Q000737:chemistry*; D006801:Humans; D017433:Protein Structure, Secondary / Q000528:radiation effects; D013997:Time Factors; D014965:X-Rays / Q000009:adverse effects
D006657:Histones