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Biocatalysts: The Different Classes and Applications for Synthesis of APIs
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
A strategy used by bacteria and fungi to produce peptides as secondary metabolites among them antibiotics (vancomycin, bacitracin), immunosuppressives (cyclosporine) or biosurfactants (surfactin) which are in part of high pharmacological/medical relevance is the nonribosomal synthesis catalyzed by large multi-enzyme complexes the so-called nonribosomal peptide synthases (NRPS) as well as the polyketide synthases (PKS, Type I–III) that, e.g., generate erythromycin, an alternative to β-lactam antibiotics (Streptomyces erythreus) or the blood cholesterol lowering lovastatin (Aspergillus terreus; Hajjaj et al., 2001). In this kind of peptide or polyketide syntheses, the role of mRNA as matrix is taken over by single modules of the enzyme complex enabling a stepwise elongation of the respective metabolite. The accepted building blocks are not restricted to the canonical amino acids but D-amino acids and modified amino acids may be also incorporated (Sieber and Marahiel, 2005).
Bacillus
Published in Dongyou Liu, Laboratory Models for Foodborne Infections, 2017
Jessica Minnaard, Ivanna S. Rolny, Pablo F. Pérez
It has been demonstrated that cell-free alcohol-soluble extracts from B. subtilis strain depolarized mitochondria of Caco-2 cells. This activity was related to the presence of amylopsin that is also produced by B. mojavensis33 where three surfactin-like compounds were detected.57 These factors had toxic effects on Vero cells with the inhibition of protein synthesis.57
Strong inhibitory activities and action modes of lipopeptides on lipase
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Mei-chun Chen, Tian-tian Liu, Jie-ping Wang, Yan-ping Chen, Qing-xi Chen, Yu-jing Zhu, Bo Liu
Interestingly, surfactants were found to produce inhibitory effects on the lipolytic efficiency of lipase by generating inactive aqueous enzyme-surfactant complexes or by blocking the congregation of enzymes at the lipid/water interface11. In fact, it has been reported that bacterial cyclic lipopeptides are the most popular amphiphilic molecules that are excellent surface active compounds12. The genus Bacillus is described as an efficient source of lipopeptide biosurfactants. The Bacillus lipopeptides are divided into three different families, including iturins, surfactins, and fengycins, consisting of a cyclic lipoheptapeptide or decapeptide with a long hydrophobic fatty acid moiety13. Surfactin is a well-known surfactant consisting of a peptide ring of seven amino acids with a β-hydroxy-fatty-acid chain that can lower the surface tension of water from 72 to 27 mN/m14. In contrast to surfactin, iturin contains a β-amino fatty acid linked to a peptide ring with seven amino acid residues, while fengycin is a cycle lipopeptide with 10 amino acid residues. It has been reported that the lipopeptide biosurfactants exhibit numerous bioactivities, such as antimicrobial, antiadhesive, antitumoral, antiviral, and hypoglycaemic activities15–17. Additionally, the Bacillus lipopeptides possess high biodegradability, biocompatibility, and high stability towards extreme environments. These remarkable properties make lipopeptides potent candidate drugs for therapeutic medical applications18.
Sageretia thea (Osbeck.) modulated biosynthesis of NiO nanoparticles and their in vitro pharmacognostic, antioxidant and cytotoxic potential
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Ali Talha Khalil, Muhammad Ovais, Ikram Ullah, Muhammad Ali, Zabta Khan Shinwari, Dilawar Hassan, Malik Maaza
Figure 13(A) presents the protein kinase enzyme inhibition potential of the biogenic nickel oxide nanoparticles. Protein kinase enzymes are considered as a crucial area for anticancer research. PK enzymes are responsible for the phosphorylation of serine–threonine and tyrosine amino acid residues that play role in the cellular differentiation, proliferation and apoptosis. Cancer is associated with the deregulated phosphorylation by PK enzymes leading to tumor growth. Therefore, particular entities which can inhibit PK enzymes are of significant interest in anticancer research. PK phosphorylation is a key factor in the formation of hyphae in Streptomyces and therefore has been extensively used to identify PK inhibitors. Streptomyces 85E strain was used to screen PK inhibition potential of the as synthesized NiO nanoparticles. Bald zones were measured in mm. Largest zone (13 mm) was recorded at 1000 μg/ml. All tested concentration produced bald zones except for 31.25 μg/ml which was found to be effective. Our results indicate that biomodulated NiO can be used as a signal transductor inhibitor in the genesis of tumor. Surfactin employed as a positive control which yielded higher zone of inhibition, that is, 18 mm at 1000 μg/ml and 7.4 mm at 31.25 μg/ml.
Inhibitory effect of a lipopeptide biosurfactant produced by Bacillus subtilis on planktonic and sessile cells of Trichosporon spp.
Published in Biofouling, 2018
Rossana de Aguiar Cordeiro, Ewerton Weslley Caracas Cedro, Ana Raquel Colares Andrade, Rosana Serpa, Antonio José de Jesus Evangelista, Jonathas Sales de Oliveira, Vandbergue Santos Pereira, Lucas Pereira Alencar, Patrícia Bruna Leite Mendes, Bárbara Cibelle Soares Farias, Vânia Maria Maciel Melo, Zoilo Pires de Camargo, Débora de Souza Collares Maia Castelo-Branco, Raimunda Sâmia Nogueira Brilhante, José Júlio Costa Sidrim, Marcos Fábio Gadelha Rocha
In order to better understand the mechanism of action of TIM96 against Trichosporon cells, the effect of the biosurfactant on the total cellular ergosterol content and membrane permeability was investigated. It was found that TIM96, at sub-inhibitory concentrations, reduced the amount of total sterols. This result may be a possible explanation for the absence of a pharmacological interaction between TIM96 and FLC verified in this study. Furthermore, the results showed that TIM96 is capable of altering the membrane integrity of Trichosporon spp., making cells more permeable to molecules such as nucleic acids and proteins. Dispersion of intracellular components suggests that one of the effects of TIM96 on fungal cell is the formation of membrane pores, or the damage of the cytoplasmic membrane, causing cell death. The release of intracellular content is considered a strong indicator of serious and irreversible damage (Devi et al. 2010). Previous studies have proposed that lipopeptide biosurfactants target the cell membrane, altering its barrier function and, then, causing cellular damage/death. Surfactin, fengicin and iturin, compounds present in TIM96, are capable of causing interactions with the plasma membrane. Surfactin is a molecule capable of performing hydrophobic interactions, through which it spontaneously penetrates the lipid membranes (Grau et al. 1999; Eeman et al. 2006). Fengicin has been reported to cause disturbances in the integrity of the cytoplasmic membrane, increasing cell permeability and lysis (Bernat et al. 2016). Iturin acts by rupturing the plasma membrane through the formation of small vesicles (Rodrigues et al. 2006). Thus, the result obtained with TIM96 reinforces the idea that biosurfactants can act on the plasma membrane, which would explain its fungicidal activity.