Production of enantiomerically pure (S)-β-phenylalanine and (R)-β-phenylalanine by penicillin G acylase from Escherichia coli in aqueous medium

2-phenylacetamide Separated from the seed of Lepidium apetalum Willd. inhibited renal fibrosis via MAPK pathway mediated RAAS and oxidative stress in SHR Rats

BACKGROUND

Renal fibrosis with Renin-angiotensin-aldosterone system (RAAS) activation and oxidative stress are one of the major complications in hypertension. 2-phenylacetamide (PA), a major active component of Lepidium apetalum Willd. (L.A), has numerous pharmacological effects. Its analogues have the effect of anti-renal fibrosis and alleviating renal injury. This study aims to explore the underlying mechanism of PA for regulating the renal fibrosis in SHR based on the MAPK pathway mediated RAAS and oxidative stress.

METHODS

The SHR rats were used as the hypertension model, and the WKY rats were used as the control group. The blood pressure (BP), urine volume were detected every week. After PA treatment for 4 weeks, the levels of RAAS, inflammation and cytokines were measured by Enzyme-Linked Immunosorbnent Assay (ELISA). Hematoxylin-Eosin staining (HE), Masson and Immunohistochemistry (IHC) were used to observe the renal pathology, collagen deposition and fibrosis. Western blot was used to examine the MAPK pathway in renal. Finally, the SB203580 (p38 MAPK inhibitor) antagonism assay in the high NaCl-induced NRK52e cells was used, together with In-Cell Western (ICW), Flow Cytometry (FCM), High Content Screening (HCS) and ELISA to confirm the potential pharmacological mechanism.

RESULTS

PA reduced the BP, RAAS, inflammation and cytokines, promoted the urine, and relieved renal pathological injury and collagen deposition, repaired renal fibrosis, decreased the expression of NADPH Oxidase 4 (NOX4), transforming growth factor-β (TGF-β), SMAD3 and MAPK signaling pathway in SHR rats. Meanwhile,,the role of PA could be blocked by p38 antagonist SB203580 effectively in the high NaCl-induced NRK52e cells. Moreover, molecular docking indicated that PA occupied the ligand binding sites of p38 MAPK.

CONCLUSION

PA inhibited renal fibrosis via MAPK signalling pathway mediated RAAS and oxidative stress in SHR Rats.

2-Phenylacetamide Isolated from the Seeds of Lepidium apetalum and Its Estrogen-Like Effects In Vitro and In Vivo

The aim of this study was to investigate the estrogen-like effects of 2-phenylacetamide (PA), which is the main compound isolated from the seeds of Lepidium apetalum Willd (LA). Results showed that LA and PA could promote the proliferation of MCF-7 cells. The mouse uterine weight test showed that, LA and PA could increase the uterus index of immature female mice, and the levels of luteinizing hormone (LH) and estrogen (E2). LA could increase the expression of ERα and ERβ, while PA could increase the expression of ERα, ERβ and GPR30 in the uterus and MCF-7 cells. In addition, co-incubation of the estrogen receptor blocker with LA or PA abolished the inductive effect of the proliferation. PA has estrogenic activities and was the material basis of LA that played the estrogenic effect. LA and PA might be used for the treatment of perimenopause syndrome in a novel application.

β-Phenylalanine Ester Synthesis from Stable β-Keto Ester Substrate Using Engineered ω-Transaminases

The successful synthesis of chiral amines from ketones using ω-transaminases has been shown in many cases in the last two decades. In contrast, the amination of β-keto acids is a special and relatively new challenge, as they decompose easily in aqueous solution. To avoid this, transamination of the more stable β-keto esters would be an interesting alternative. For this reason, ω-transaminases were tested in this study, which enabled the transamination of the β-keto ester substrate ethyl benzoylacetate. Therefore, a ω-transaminase library was screened using a coloring o-xylylenediamine assay. The ω-transaminase mutants 3FCR_4M and ATA117 11Rd show great potential for further engineering experiments aiming at the synthesis of chiral (S)- and (R)-β-phenylalanine esters. This alternative approach resulted in the conversion of 32% and 13% for the (S)- and (R)-enantiomer, respectively. Furthermore, the (S)-β-phenylalanine ethyl ester was isolated by performing a semi-preparative synthesis.

Quantifying the efficiency of Saccharomyces cerevisiae translocation tags

Compartmentalization of metabolic pathways into organelles of the yeast Saccharomyces cerevisiae has been used to improve chemical production. Pathway compartmentalization aids chemical production by bringing enzymes into close proximity to one another, placing enzymes near key starting metabolites or essential co-factors, increasing the effective concentration of metabolic intermediates, and providing a more suitable chemical environment for enzymatic activity. Although several translocation tags have been used to localize enzymes to different yeast organelles, their translocation efficiencies have not been quantified. Here, we systematically quantify the translocation efficiencies of 10 commonly used S. cerevisiae tags by localizing green fluorescent protein (GFP) into three yeast organelles: the mitochondrion (4 tags), the vacuole (3 tags), and the peroxisome (3 tags). Further, we investigate whether plasmid copy number or mRNA levels vary with tag translocation efficiency. Quantification of the efficiencies of S. cerevisiae translocation tags provides an important resource for bioengineering practitioners when choosing a tag to compartmentalize their desired protein. Finally, these efficiencies can be used to determine the percentage of enzyme compartmentalization and, thus, help better quantify effects of compartmentalization on metabolic pathway efficiency.