Identification of novel CYP4F2 genetic variants exhibiting decreased catalytic activity in the conversion of arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE)

CYP4F2 is an enzyme involved in the formation of 20-hydroxyeicosatetraenoic acid (20-HETE) from arachidonic acid and metabolizes vitamin K into an inactive form. Our objectives were to identify new CYP4F2 genetic variants and to characterize the functional consequences of the conversion of arachidonic acid into 20-HETE. We used direct DNA sequencing to identify a total of 20 single-nucleotide polymorphisms (SNPs) including four coding variants, A27V, R47C, P85A, and V433M, in 50 randomly selected subjects. Of these, A27V and P85A were new. Recombinant variant proteins were prepared using an Escherichia coli expression system, purified, and quantified via CO-difference spectral analysis. The conversion of arachidonic acid to 20-HETE by the coding variants was compared to that of the wild-type protein. Wild-type CYP4F2 exhibited the highest intrinsic clearance, followed by P85A, A27V, V433M, and R47C (40-65% of the wild-type value). The locations of the mutated residues in the three-dimensional protein structure were predicted by structural modeling, and the possible effects on 20-HETE synthesis discussed. In summary, we describe the allele frequency, haplotype distribution, and linkage disequilibrium of CYP4F2 and functionally analyze the CYP4F2 coding variants. Our findings suggest that individuals having the low-activity alleles of CYP4F2 may inefficiently convert arachidonic acid into 20-HETE. This may aid in our understanding of 20-HETE-related blood pressure problems and cardiovascular diseases when genotype-phenotype association studies are performed in the future.