Publications by authors named "Mikhail V Karpov"
Article Synopsis
- Cytochrome CYP102A1 (P450 BM3) from Priestia megaterium is a promising candidate for directed evolution due to its unique functions and ability to hydroxylate androstanes into bioactive products.
- The study focused on expressing a mutant form of this enzyme, CYP102A1-LG23, in Mycolicibacterium smegmatis BD, achieving successful conversion of androst-4-ene-3,17-dione into 7β-OH-AD.
- Co-expressing the mutant enzyme with glucose dehydrogenase (GDH) led to a significant increase in hydroxylation yield, demonstrating the potential for engineered bacteria to produce valuable steroid compounds.
Cholesterol determination by cholesterol oxidase reaction is a fast, convenient, and highly specific approach with widespread use in clinical diagnostics. Routinely, endpoint measurements with 4-aminophenazone or 4-aminoantipyrine as chromogens and sodium cholate, surfactants, or alcohols as solubilizing agents are used. Here we describe a novel kinetic method to determine cholesterol in 0.
View Article and Find Full Text PDFThe main male hormone, testosterone is obtained from cheap and readily available phytosterol using the strains of Mycolicibacterium neoaurum VKM Ac-1815D, or Ac-1816D. During the first "oxidative" stage, phytosterol (5-10 g/L) was aerobically converted by Ac-1815D, or Ac-1816D to form 17-ketoandrostanes: androstenedione, or androstadienedione, respectively. At the same bioreactor, the 17-ketoandrostanes were further transformed to testosterone due to the presence of 17β-hydroxysteroid dehydrogenase activity in the strains ("reductive" mode).
View Article and Find Full Text PDFCholesterol oxidase is a highly demanded enzyme used in medicine, pharmacy, agriculture, chemistry, and biotechnology. It catalyzes oxidation of 3β-hydroxy-5-ene- to 3-keto-4-ene- steroids with the formation of hydrogen peroxide. Here, we expressed 6xHis-tagged mature form of the extracellular cholesterol oxidase (ChO) from the actinobacterium Nocardioides simplex VKM Ac-2033D (55.
View Article and Find Full Text PDFArticle Synopsis
- Cytochrome P450scc (CYP11A1) is an enzyme that converts cholesterol into pregnenolone but has low activity with β-sitosterol.
- The study aimed to identify specific amino acid changes in the enzyme that could enhance its ability to convert β-sitosterol.
- Despite modifying the active site through mutations, the results showed that these changes actually decreased enzyme activity, highlighting the crucial roles of specific amino acid residues in the enzyme's function.