Evidence for dna endonuclease activity in nuclear extracts from mosquito cells

Gerald D. Baldridge, Ann M. Fallon

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


We describe a deoxyribonuclease activity from nuclear protein extracts of cultured Aedes albopictus mosquito cells. The nuclease cleaved linear and circular double-stranded DNA, first generating 3′ OH single-stranded nicks followed by second strand cleavage, but had little or no exonucleolytic activity. Detection of this activity was optimal at pH 7.1, in the presence of a divalent cation (Mg2+, Ca2+, Mn2+, Ba2+). In the presence of Mg2+, Zn2+, Hg2+ and Cu2+ inhibited activity, sulfhydryl reagents and ATP had no effect. At physiological temperatures (18-35°C), linear double-stranded DNA probes were preferentially cleaved near sites containing 3-6 consecutive deoxyadenine/thymine base pairs. Results from salt dependency and drug inhibition studies, combined with inspection of DNA sequence, suggested that DNA structure is among the parameters that determine preferred cleavage sites.

Original languageEnglish (US)
Pages (from-to)17-32
Number of pages16
JournalComparative Biochemistry and Physiology -- Part B: Biochemistry and
Issue number1
StatePublished - Jan 1995

Bibliographical note

Funding Information:
Acknowledgements--Twhoisr k was supportedb y NIH grant no. AI20385a nd by the Universityo f MinnesotaA griculturalE xperimenSt tation( contri-butionn o.20818).


  • DNA structure
  • Divalent cation
  • Endonuclease
  • Insect
  • Mosquito
  • Nuclease


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