An important direction of research in increasing the effectiveness of cancer therapies is the design of effective drug distribution systems in the body. The development of the new strategies is primarily aimed at improving the stability of the drug after administration and increasing the precision of drug delivery to the destination. Due to the characteristic features of cancer cells, distributing chemotherapeutics exactly to the microenvironment of the tumor while sparing the healthy tissues is an important issue here. One of the promising solutions that would meet the above requirements is the use of Magnetotactic bacteria (MTBs) and their organelles, called magnetosomes (BMs). MTBs are commonly found in water reservoirs, and BMs that contain ferromagnetic crystals condition the magnetotaxis of these microorganisms. The presented work is a review of the current state of knowledge on the potential use of MTBs and BMs as nanocarriers in the therapy of cancer. The growing amount of literature data indicates that MTBs and BMs may be used as natural nanocarriers for chemotherapeutics, such as classic anti-cancer drugs, antibodies, vaccine DNA, and siRNA. Their use as transporters increases the stability of chemotherapeutics and allows the transfer of individual ligands or their combinations precisely to cancerous tumors, which, in turn, enables the drugs to reach molecular targets more effectively.

Objective Regio-and stereoselective hydroxylation of lithocholic acid (LCA) using CYP107D1 (OleP), a cytochrome P450 monooxygenase from the oleandomycin synthesis pathway of Streptomyces antibioticus. Results Co-expression of CYP107D1 from S. antibioticus and the reductase/ferredoxin system PdR/PdX from Pseudomonas putida was performed in Escherichia coli whole cells. In vivo hydroxylation of LCA exclusively yielded the 6b-OH product murideoxycholic acid (MDCA). In resting cells, 19.5% of LCA was converted to MDCA within 24 h, resulting in a space time yield of 0.04 mmol L-1 h-1. NMR spectroscopy confirmed the identity of MDCA as the sole product. Conclusions The multifunctional P450 monooxygenase CYP107D1 (OleP) can hydroxylate LCA, forming MDCA as the only product.

Shikimic acid 3-phosphate, as a central metabolite of the shikimate pathway, is of high interest as enzyme substrate for 5-enolpyruvoyl-shikimate 3-phosphate synthase, a drug target in infectious diseases and a prime enzyme target for the herbicide glyphosate. As the important substrate shikimic acid 3-phosphate is only accessible via a chemical multi-step route, a new straightforward preparative one-step enzymatic phosphorylation of shikimate using a stable recombinant shikimate kinase has been developed for the selective phosphorylation of shikimate in the 3-position. Highly active shikimate kinase is produced by straightforward expression of a synthetic aroL gene in Escherichia coli. The time course of the shikimate kinase-catalyzed phosphorylation is investigated by H- and P-NMR, using the phosphoenolpyruvate/pyruvate kinase system for the regeneration of the ATP cofactor. This enables the development of a quantitative biocatalytic 3-phosphorylation of shikimic acid. After a standard workup procedure, a good yield of shikimic acid 3-phosphate, with high HPLC- and NMR purity, is obtained. This efficient biocatalytic synthesis of shikimic acid 3-phosphate is superior to any other method and has been successfully scaled up to multi-gram scale.

The biocatalytic asymmetric Michael addition ofl-arginine to fumarate using argininosuccinate lyase (ASL) has enabled the synthesis of the key metabolitel-argininosuccinic acid lithium salt1for the first time, with excellent yield and purity.

The Nω‐phospho‐l‐arginine energy‐buffering system is mainly present in invertebrates for regulating energy requirements when it is highly needed, such as in the flight muscles of an insect or when energy supply fluctuates, as in the medically important protozoa Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major. The lack of availability of this important metabolite was due to a tedious chemical procedure, by which Nω‐phospho‐l‐arginine was prepared in over 5 reaction steps in a low yield. Therefore, we aimed at improving the synthetic methodology for the preparation of this important metabolite. As site‐ and enantioselective kinases have been very useful catalysts for biocatalytic phosphorylations in straightforward syntheses of phosphorylated metabolites, a stable and selective arginine kinase has been selected for the selective phosphorylation of l‐arginine. The Arg gene has been cloned and expressed in E. coli and a highly active arginine kinase has been prepared. A simple synthesis of Nω‐phospho‐l‐arginine has been developed by arginine kinase catalyzed phosphorylation of l‐arginine combined with the recycling of the phosphorylating agent ATP by using the phosphoenolpyruvate/pyruvate kinase system. After standard work‐up, the desired product Nω‐phospho‐l‐arginine was obtained in gram quantities and in one step.