Some properties of a DNA-unwinding protein unique to lymphocytes from chronic lymphocytic leukemia.

Published

Journal Article

Lymphocytes from a common human leukemia, chronic lymphocytic leukemia, chronic lymphocytic leukemia, have a greatly enhanced capability of DNA repair and a concomitantly prolonged survival in vitro after damage to DNA. From these lymphocytes, we isolated and purified a DNA-binding protein with a molecular weight of 24,000. It binds tightly to both ultraviolet light (UV)-irradiated and single-stranded DNA. At 35 degrees it enhances the helix-coil transition of poly[d(A-T)] AND the UV-irradiated calf thymus DNA but is inefficient in ordinary native DNA. This protein also facilitates the rate of UV-endonuclease incision of UV DNA but does not induce any nicks by itself. This finding suggests that the protein may be involved in DNA repair by enhancing such activity, and also offers an explanation for our observation of increased DNA repair in chronic lymphocytic leukemia cells. When human metaphase chromosomes are exposed to the protein, it induces marked lengthening of chromatids suggesting that this protein may also act on complex chromosomes. By quantitative immunochemical determinations, such protein could not be found in lymphocyte extracts of three normal individuals.

Full Text

Duke Authors

Cited Authors

  • Huang, AT; Riddle, MM; Koons, LS

Published Date

  • April 1, 1975

Published In

Volume / Issue

  • 35 / 4

Start / End Page

  • 981 - 986

PubMed ID

  • 1116155

Pubmed Central ID

  • 1116155

International Standard Serial Number (ISSN)

  • 0008-5472

Language

  • eng

Conference Location

  • United States