Question

Pharmacogenomic Question:

What would happen with affinity and dissociation constant if there is a SNP at the binding site?

Answer 1

SNP stands for SINGLE MUCLEOTIDE POLYMORPHISM which is simplest form of variation in DNA. In a sequence one nucleotide get replaced by another nucleotide and called polymorphism. these mutations are found very frequently i.e. present after nearly every1000 bps in genome contributing to about millions of SNP in whole genome. these mutations are found to be stable and not deleterious.

Mostly these mutations are anonymous and can cause loss of function of protein due to change in amino acid coded by mutated DNA. Some mutation have positive effect whereas some mutation can have negative effect.

For example in a sequence C is replaced by A which can result in same or different amino acid. Same amino acid will not change the sequence but differentr amino acid might effect the affinity of transcription factor to sequence or can cause change in structure of newly formed protein resulting in non functional or degenrated protein causing diseases like cancer, sickle cell anemia etc.

Affinity and dissociation constant can either be reduced or promoted depending on the nature of mutation or polymorphism.