末端脱氧核苷酸转移酶

物理性质

性状：冷冻干燥含氯化钾的固体。

作用与用途

Analysis Note Activity assay: 200 mM potassium cacodylate, pH 7.2, 4 mM MgCl2, 1 mM 2-mercaptoethanol, 1 mM 3H-dATP, 70 μM d(pT)6, 37 °C.
Biochem/physiol Actions Bovine terminal transferase (TdT) is a primer-dependent polymerase that catalyzes the addition of deoxynucleotides to the 3′-OH terminus of DNA molecules with the release of inorganic phosphate. TdT reacts preferentially with either single-stranded DNA molecules or double-stranded-DNA with 3′ overhangs, but procedures have been developed to label blunt ends or 3′-recessive ends. In a reaction mixture, the divalent ion (Co2+, Mn2+, Mg2+) will influence purine and pyrimidine polymerization rate. Activities of TdT are also affected by the bases (dATP, dCTP, dGTP and dTTP) present. Each reaction mixture needs to be optimized. The enzyme is commonly used to add complementary homopolymer tails to vector and insert DNA for construction of recombinant DNA in vitro.
Features and Benefits ? Add homopolymers to vectors, inserts and cDNA for cloning
? Label the 3′-end of double- and single-stranded DNA with non-radioactive and radioactive labels
? Carry out in vitro mutagenesis by adding single nucleotides to DNA
? Use in TUNEL assays with deoxyuridine triphosphate (dUTP) conjugated with a fluorescent chromophore or biotin to label nicked DNA in apoptotic cells

Unit Definition One unit will incorporate 1 nanomole of dATP into acid-precipitable material in one hour at 37 °C using d(pT)6 as primer.
Physical form Solution in 50 mM potassium phosphate, pH 7.4, 1 mM 2-mercaptoethanol and 50% glycerol (v/v)

性质与稳定性

生化研究

贮存方法

充氩-20°C密闭，避光，通风干燥处

生态学数据

通常对水是不危害的，若无政府许可，勿将材料排入周围环境。