In the scope of this applicable scientiffic publication, we have carried out activities with the aim to identify a new lipstatin-producing strain. Lipstatin is inhibitor of pancreatic lipase of medical importance. Authors focused their work on isolation of new strain, potentialy producing less lipstatin-related impurities, which are biosynthesised due to promiscous nature of the enzymes involved in the provision of building blocks. A new strain, Streptomyces virginiae CBS 314.55 was isolated by dereplication screening approach based on the taxonomic criteria. Promiscuity of the selected enzymes from primary metabolism involved in the provision of building blocks for lipstatin biosynthesis was described in the patent application EP2141236. The work described in this research article describes isolation of new strain producing lipstatin with different profile of impurities. Some of the methodological approaches in this paper relate to the work in the scope of this project.
COBISS.SI-ID: 4372088
In this good quality paper where we report study of the enzyme complex (pathway) involved in the formation of ellyl and methylmalonyl pathway, building blocks activated by AT4 domain from FK506 PKS complex of medically important immunosuppression drug which is central part of this ARRS funded project. We demonstrated that the crotonyl CoA-reductase (CCR) is a central enzyme in this pathway. We have identified a second homologue, located in ethylmalonyl-CoA pathway (EMC). WE have demonstrated that these two CCR homologues do not interact, although their homology on the DNA and amino acid level is very high. Their activities are separated by different expression-timing in the natural strain of S. tsukubaensis. In addition, their expression is dependant on the source of carbon. Interestingly, while in EMC pathway metabolites are CoA-activates, in the FK506 gene cluster allylmalonate is ACP activated, which directly influences this study. This paper brings very important understanding on the FK506 regulation and production of FK506-related impurities of high commercial importance.
COBISS.SI-ID: 4572536
The new approach for the synthesis of masked analoques of phosphopanthotenate was developed. Following this new methodology we prepared related chlorophosphate reagents and developed one new in the series for a introduction of (isobutyryloxy)methyl phosphate group into panthothenate backbone. This new approach and new knowledge obtained was also used in the scope of this project and can be further used for other potentially bioactive molecules bearing free hydroxyl functionality.
COBISS.SI-ID: 4655736
The article describes a comparison of a natural and industrial hih-producing strain of Saccharopolyspora erythraea using genomic, transcriptomic and proteomic analysis as well as subsequent data integration using systems biology approach. The main objective was to identify differences between the two strains which have key influence on increased yield of industrially very important antibiotic erythromycin. For the first time we carried out such comparative analysis using industrially relevant bioprocess conditions, including industrial ingredients and cultivation in the pilot bioreactors of the company Acies Bio. Our main conclusions were that in the industrial strain enzymes involved in erythromycin biosynthesis, metabolism of branched chain amino acids and proteolysis were most strongly upregulated in the HP strain. Interestingly, genes related to TCA cycle and DNA-repair were downregulated. Based on this work we identified a novel metabolic pathway towards the precursor methylmalonyl-CoA and generated novel strains with increased yield of erythromycin, which was important also for the implementation of this project.
COBISS.SI-ID: 4655992
Antimicrobial resistance and the shortage of novel antibiotics have led to an urgent need for new antibacterial drug leads. Several existing natural product scaffolds (including chelocardins) have not been developed because their suboptimal pharmacological properties could not be addressed at the time. It is demonstrated here that reviving such compounds through the application of biosynthetic engineering can deliver novel drug candidates. In this paper, through a rational approach, the carboxyamido moiety of tetracyclines (an important structural feature for their bioactivity) was introduced into the chelocardins, which are atypical tetracyclines with an unknown mode of action. A broadspectrum antibiotic lead was generated with significantly improved activity, including against all Gram-negative pathogens of the ESKAPE panel. Since the lead structure is also amenable to further chemical modification, it is a platform for further development through medicinal chemistry and genetic engineering. By application of biosynthetic engineering, we have influenced selectivity of acyltransferase and other enzymes of minimal PKS. This is enzymes complec realtively similar to the enzyme complex involved in the biosynthesis of unusual extender unit in the biosynthesis of FK506, in the scope of this project.
COBISS.SI-ID: 4486520