How do alkylating agents cause mutations?

1 Answer
Mar 27, 2017

Alkylating agents usually induce mispairing between bases.


Alkylating agents transfer methyl or ethyl groups to bases or the backbone phosphate group. As a consequence,the altered bases pair with the wrong complement. This either disrupts base pairing directly or causes loss of bases. Which ever ways, this leads to faulty DNA replication or repair.

For example when guanine is alkylated it can be mispaired with thymine.
Mustard gas, vinyl chloride, nitroso amines and ethyl nitrosourea are some alkylating agents.

Therapeutic versions of alkylating agents often inhibit cancer growth by interfering with the replication of DNA I rapidly dividing cancer cells.