A possible cause of heterogeneity of mammalian apurinic/apyrimidinic endonuclease.
1. Mammalian major apurinic/apyrimidinic (AP) endonuclease, APEX nuclease (M(r) 35.4 kDa) was purified from HeLa cells. A hybrid protein (M(r) 36.4 kDa), which was expressed in BW2001 strain cells of E. coli, comprising human APEX nuclease headed by 10 additional amino acids was also purified. 2. The purified preparations were frequently associated with 31-, 33- and 35-kDa peptides having AP endonuclease activity. 3. The 33- and 35-kDa peptides were suggested to be formed from the hybrid protein or APEX nuclease during their purification processes by proteolytic cleavage with subtilisin-like protease. The 31-kDa peptide was thought to be produced by chemical cleavage of the aspartyl-prolyl bond of APEX nuclease. 4. The results support the notion that some of AP endonuclease heterogeneity based on the molecular weight difference are caused by proteolytic (and chemical) cleavage of a species of AP endonucleases during the extraction and purification.
Seki
S
S
Department of Molecular Biology, Okayama University Medical School, Japan.
Takata
A
A
Nakamura
T
T
Akiyama
K
K
Watanabe
S
S
D000596:Amino Acids / Q000235:genetics / Q000378:metabolism; D000818:Animals; D003001:Cloning, Molecular; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043223:Deoxyribonuclease IV (Phage T4-Induced); D004591:Electrophoresis, Polyacrylamide Gel; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D006367:HeLa Cells; D006801:Humans; D010446:Peptide Fragments / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D000596:Amino Acids; D029968:Escherichia coli Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D004706:Endodeoxyribonucleases; D043223:Deoxyribonuclease IV (Phage T4-Induced); C468972:endonuclease IV, E coli; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase