Cancer Science & Therapy

An Atypical DNA Polymerase Beta Overexpressed in Human Aml/Hl-60 Malignant Cells

Abstract

Alexander A Bukhvostov, Oleg A Shatalov, Alexey P Orlov and Dmitry A Kuznetsov

Human acute myeloid leukemia cells overexpresses a beta–like DNA polymerase (EC 2.7.7.7) which is found
to be a chromatin associated single subunit protein (66.5 kDa) purified by original extraction/gel filtration procedure
allowing to gain the 122,000-fold purification degree as corrected to a total cell protein. The enzyme possesses
some key DNA pol β-specific catalytic properties such as the processing of short (200n-250n) single strand DNA
sequences, activation in the presence of 200 mM KCl, resistance to N-ethyl-melamide and Aphidicolin, lack of
3’,5’-exonuclease activity, and low dTTP utilization rates (KM=0.016 mM, Kcat=0.622 (μM dTTP/min)/mg protein). A
possible significance of the unique enzyme studied as a target for its pharmaceutical inhibitors is under discussion.
This work is a full–length version of a study presented as a Poster at the OMICS managed 2nd World Congress on
Science Cancer and Therapy, Sept 10–12, 2012, San Antonio, TX.