RESUMO
Although triphenyltin (TPT) degradation pathway has been determined, information about the enzyme and protein networks involved was severely limited. To this end, a cytochrome P450 hydroxylase (CYP450) gene from Bacillus thuringiensis was cloned and expressed in Escherichia coli BL21 (DE3), namely E. coli pET32a-CYP450, whose dosage at 1gL-1 could degrade 54.6% TPT at 1mgL-1 within 6 d through attacking the carbon-tin bonds of TPT by CYP450. Sequence analysis verified that the CYP450 gene had a 1214bp open reading frame, encoding a protein with 404 amino acids. Proteomic analysis determined that 60 proteins were significantly differentially regulated expression in E. coli pET32a-CYP450 after TPT degradation. The up-regulated proteins enriched in a network related to transport, cell division, biosynthesis of amino acids and secondary metabolites, and microbial metabolism in diverse environments. The current findings demonstrated for the first time that P450 received electrons transferring from NADH could effectively cleave carbon-metal bonds.
Assuntos
Sistema Enzimático do Citocromo P-450/genética , Poluentes Ambientais/análise , Escherichia coli/metabolismo , Compostos Orgânicos de Estanho/análise , Proteoma/metabolismo , Sequência de Aminoácidos , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Biodegradação Ambiental , Clonagem Molecular , Sistema Enzimático do Citocromo P-450/metabolismo , Transporte de Elétrons , Poluentes Ambientais/química , Escherichia coli/genética , Dados de Sequência Molecular , Compostos Orgânicos de Estanho/química , ProteômicaRESUMO
The effects of hexabromocyclododecane (HBCD) on the relationship between physiological responses and metabolic networks remains unclear. To this end, cellular growth, apoptosis, reactive oxygen species, exometabolites and the proteome of Escherichia coli were investigated following exposure to 0.1 and 1 µM HBCD. The results showed that although there were no significant changes in the pH value, apoptosis and reactive oxygen species under HBCD stress, cell growth was inhibited. The metabolic network formed by glycolysis, oxidative phosphorylation, amino acids biosynthesis, membrane proteins biosynthesis, ABC transporters, glycogen storage, cell recognition, compound transport and nucleotide excision repair was disrupted. Cell chemotaxis and DNA damage repair were the effective approaches to alleviate HBCD stress. This work improves our understanding of HBCD toxicity and provides insight into the toxicological mechanism of HBCD at the molecular and network levels.
Assuntos
Escherichia coli , Apoptose , Retardadores de Chama , Hidrocarbonetos Bromados , Espécies Reativas de OxigênioRESUMO
Although the inhibitor of apoptosis proteinlike protein2 (ILP2) has been shown as a serological biomarker for breast cancer, its effect on breast cancer cell growth remains elusive. The present study aimed to determine the role of ILP2 in breast cancer cell growth. We used immunohistochemistry to analyze ILP2 expression in 59 tissue paraffinembedded blocks, which included 35 breast cancer tissues and 24 galactophore hyperplasia tissues. Western blot analysis was used to detect protein expression levels of ILP2 in breast cancer cell lines such as HCC1937, MX1 and MCF7 as well as breast gland cell line MCF 10A. ILP2 was silenced by siRNA in HCC1937, MX1 and MCF7 cell lines. MTT assays, scratch assays and AOEB double staining analysis were conducted to evidence the role of ILP2 on breast cancer cell growth. Results from this study showed increased ILP2 expression in breast cancer tissues and breast cancer cell lines such as HCC1937, MX1 and MCF7. Cell viability or rate of cell migration of HCC1937, MX1 and MCF7 cell lines was significantly inhibited when ILP2 was knocked down by siRNA. The apoptosis rate of HCC1937, MX1 and MCF7 cell lines was increased when compared with that of the control group. Thus, ILP2 plays an active role in the growth of breast cancer cells.