Biochemical characterization of variants of canine CYP1A1 using heterologousexpression

The Journal of Veterinary Medical Science

YoungMin YUN¹  Seung Heon LEE²  Seungwoo LEE²  Dayoung OH²  Hee Jeong YU²  Doug-Young RYU²  Yu Jung CHOI²  Ki-Hoan NAM³ 

[1] College of Veterinary Medicine, Jeju NationalUniversity, Jeju, 63243, Republic of Korea;College of Veterinary Medicine, Research Institute forVeterinary Sciences, BK21plus Program for Creative Veterinary Science Research, SeoulNational University, Seoul, 08862, Republic of Korea;Laboratory Animal Resource Center, Korea ResearchInstitute of Bioscience and Biotechnology, Cheongwon, Chungbuk, 28116 Republic ofKorea

关键词: CYP1A1;    dog;    enzyme activity;    heme;    holoenzyme;   

DOI  :  10.1292/jvms.17-0192

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

Cytochrome P450 1A1 (CYP1A1) is a heme-containing mono-oxygenase involved in metabolismof environmental contaminants. Two variants of dog CYP1A1 with a single residue differencewere identified and designated Sap1 and Sap2. Compared with Sap1, Sap2 had a Trp50Leusubstitution. The biochemical characteristics of the variants were comparatively analyzedusing heterologous expression in Escherichia coli. The membrane fractionof E. coli expressing Sap2 exhibited higher CYP holoprotein and hemecontents than the Sap1-containing membranes, although the level of total CYP1A1 protein(i.e., apoprotein + holoprotein) was comparable between the groups. As normalized toholo-CYP content, the Sap2-expressing membranes showed lower CYP1A1-specific enzymeactivities, such as 7-ethoxyresorufin O-dealkylation (EROD), than theSap1 group. In single substitution variants of residue 50, proteins with hydrophobicresidues having mass similar to Leu exhibited lower EROD activities than those withhydrophobic residues having larger mass than Leu. In addition, variants with polar orcharged residues having mass similar to Leu showed activities that were comparable tothose of Sap2. Taken together, these findings suggest that the Trp50Leu substitution leadsto an enhancement of holo-CYP1A1 formation, but diminishes the enzyme activity because ofthe small size of Leu compared with Trp.

【 授权许可】

Unknown