Open AccessDouble‐Stranded Polydeoxyribonucleotides Containing 6‐Thiodeoxyguanosine and 6‐Thiodeoxyinosine
Author(s) -
BEIKIRCH Hartmut H.,
LEZIUS Axel G.
Publication year - 1972
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1972.tb01848.x
Subject(s) - micrococcus luteus , polynucleotide , circular dichroism , thermal stability , polymerization , stereochemistry , chemistry , materials science , polymer , escherichia coli , biochemistry , organic chemistry , gene
Three new double‐stranded polydeoxyribonucleotides containing the nucleoside analogs 6‐thiodeoxyguanosine and 6‐thiodeoxyinosine were synthesized enzymatically. Poly[d(A‐C) · d(T‐s 6 G)] and poly[d(A‐s 6 G) · d(T‐C)] were prepared by extensive synthesis with DNA polymerase from Micrococcus luteus , while the same enzyme from Escherichia coli failed in extensive polymerisation but brought about the synthesis of poly[d(T‐s 6 G)] and poly[d(T‐s 6 I)] by the repair mechanism using single‐stranded poly[d(A‐C)] template and a minute amount of d(T‐G) n primer. The analog‐containing DNAs were characterized by ultraviolet absorption and circular dichroism spectra as well as by their stability against thermal and alkaline denaturation. The substitution by 6‐thiodeoxyguanosine or 6‐thiodeoxyinosine for deoxyguanosine reduces the stability of the biopolymers considerably. Exchange of the analog‐containing strand by singlestranded poly[d(T‐G)] takes place rapidly even at ambient temperature.