Equilibrium Binding Constants of C3DP, A Nucleic Acid-Binding Protein Isolated from Human Serum
- 1 January 1981
- journal article
- research article
- Published by Walter de Gruyter GmbH in Hoppe-Seyler´s Zeitschrift Für Physiologische Chemie
- Vol. 362 (2) , 1599-1608
- https://doi.org/10.1515/bchm2.1981.362.2.1599
Abstract
The malignancy-associated [complement component C3 derived] DNA-binding protein C3DP was isolated from normal human serum and identified by dodecyl sulfate/polyacrylamide gradient gel electrophoresis and immunodiffusion. The binding of purified C3DP to DNA and RNA was investigated by density gradient centrifugation. The equilibrium binding constant K of C3DP binding to native human [spleen] DNA was determined to be K = (2.9 .+-. 0.5) .times. 105 M-1. From this value it is concluded that C3DP binds non-specifically with regard to the base sequence of the DNA. K was found to be in the same order of magnitude when measured with single-stranded or double-stranded DNA of varying G + C content, and with [mouse leukemia L5178Y cells] RNA. It varied only slightly with the pH or ionic strength of the medium, indicating that only 1 Na ion is released from DNA when 1 molecule of C3DP is bound. Ionic interactions cannot account for the stability of the C3DP-DNA complex and therefore H-bonds and hydrophobic interactions are likely to be formed.This publication has 29 references indexed in Scilit:
- Theoretical aspects of DNA-protein interactions: Co-operative and non-co-operative binding of large ligands to a one-dimensional homogeneous latticePublished by Elsevier ,2004
- Identification of a major human serum DNA-binding protein as β1H of the alternative pathway of complement activationBiochemical and Biophysical Research Communications, 1980
- Malignancy-Associated DNA-Binding Protein C3DP from Human Serum. Further Characterization and Purification of C3DP Retaining its DNA-Binding AffinityHoppe-Seyler´s Zeitschrift Für Physiologische Chemie, 1979
- Nonspecific DNA binding of genome-regulating proteins as a biological control mechanism: Measurement of DNA-bound Escherichia coli lac repressor in vivoProceedings of the National Academy of Sciences, 1977
- Ion effects on ligand-nucleic acid interactionsJournal of Molecular Biology, 1976
- Third component of complement (C3): structural properties in relation to functions.Proceedings of the National Academy of Sciences, 1975
- DNA-Binding proteins in human serumBiochemical and Biophysical Research Communications, 1975
- lac repressor-operator interaction: I. Equilibrium studiesJournal of Molecular Biology, 1970
- PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENTJournal of Biological Chemistry, 1951