POLARIZED-LIGHT SCATTERING OF NUCLEOSOMES AND POLYNUCLEOSOMES - INSITU AND INVITRO STUDIES

被引:26
作者
DIASPRO, A
BERTOLOTTO, M
VERGANI, L
NICOLINI, C
机构
[1] Institute of Biophysics, School of Medicine, University of Genoa, 16153 Genova-Sestri, Ponente
关键词
D O I
10.1109/10.83568
中图分类号
R318 [生物医学工程];
学科分类号
0831 ;
摘要
Nucleosomes, chromatin and nuclei, extracted from rat hepatocytes, are studied by a new "in house" experimental configuration which measures circular intensity differential scattering (CIDS) and other elements of the polarized light scattering matrix. The Mueller matrix elements, S14 and S34, that are related to the geometric parameters of the superhelical arrangement of polynucleosomes point to the existence of a quaternary structure at low ionic strength for chromatin prepared by the cold-water method, which is lost by shearing, and is not found in the soluble chromatin prepared through the nuclease method. Only salt addition to a final concentration of 5 mM MgCl2, 150 mM NaCl and 10 mM Tris HCl (pH 7) yields a sizeable (S14 + S34) signal in the latter chromatin, which is however still different from the corresponding signal of native nuclei and of "cold-water" chromatin. Comfortingly, the (S14 + S34) signal from isolated nucleosomes is consistently very low (nearly zero) as predicted by multiple dipole simulation within the framework of classical electrodynamics. Results are discussed in terms of the topological constraints present in the native long chromatin fiber, which are lost after limited nuclease digestion and after shearing.
引用
收藏
页码:670 / 678
页数:9
相关论文
共 40 条
[1]  
Abramowitz M., 1965, HDB MATH FUNCTIONS
[2]   AFFINITY CHROMATOGRAPHIC PURIFICATION OF NUCLEOSOMES CONTAINING TRANSCRIPTIONALLY ACTIVE DNA-SEQUENCES [J].
ALLEGRA, P ;
STERNER, R ;
CLAYTON, DF ;
ALLFREY, VG .
JOURNAL OF MOLECULAR BIOLOGY, 1987, 196 (02) :379-388
[3]  
BELMONT A, 1968, J THEOR BIOL, V90
[4]   DIFFERENTIAL SCATTERING OF CIRCULARLY POLARIZED-LIGHT BY CHROMATIN MODELED AS A HELICAL ARRAY OF DIELECTRIC ELLIPSOIDS WITHIN THE BORN APPROXIMATION [J].
BELMONT, AS ;
ZIETZ, S ;
NICOLINI, C .
BIOPOLYMERS, 1985, 24 (07) :1301-1321
[5]   A 3-DIMENSIONAL APPROACH TO MITOTIC CHROMOSOME STRUCTURE - EVIDENCE FOR A COMPLEX HIERARCHICAL ORGANIZATION [J].
BELMONT, AS ;
SEDAT, JW ;
AGARD, DA .
JOURNAL OF CELL BIOLOGY, 1987, 105 (01) :77-92
[6]  
BICKEL W S, 1981, Journal of Biological Physics, V9, P53, DOI 10.1007/BF01987283
[7]   APPLICATION OF POLARIZATION EFFECTS IN LIGHT-SCATTERING - NEW BIOPHYSICAL TOOL [J].
BICKEL, WS ;
DAVIDSON, JF ;
HUFFMAN, DR ;
KILKSON, R .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1976, 73 (02) :486-490
[8]  
Bohren C. F., 2008, ABSORPTION SCATTERIN
[9]   EXPRESSIONS FOR THE INTERPRETATION OF CIRCULAR INTENSITY DIFFERENTIAL SCATTERING OF CHIRAL AGGREGATES [J].
BUSTAMANTE, C ;
MAESTRE, MF ;
KELLER, D .
BIOPOLYMERS, 1985, 24 (08) :1595-1612
[10]   CIRCULAR DIFFERENTIAL SCATTERING CAN BE AN IMPORTANT PART OF THE CIRCULAR-DICHROISM OF MACROMOLECULES [J].
BUSTAMANTE, C ;
TINOCO, I ;
MAESTRE, MF .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES, 1983, 80 (12) :3568-3572