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Intracellular Peptide Turnover: Properties and Physiological Significance of the Major Peptide Hydrolases of Brain Cytosol
Published in Gerard O’Cuinn, Metabolism of Brain Peptides, 2020
The pyroglutamyl peptidase I gene has been cloned from bacteria. The cDNA from Bacillus subtilis encodes a protein of 23.8 kDa, whose sequence is not homologous to any sequence in the data bank149. The enzyme, over-expressed in E. Coli, could be purified in a single step by phenyl Sepharose chromatography. Gel filtration yielded a molecular weight of 80 kDa indicating a tetrameric structure150. The gene from Bacillus amyloliquefaciens has also been cloned151. The cDNA encodes a protein of 23.3 kDa. This enzyme is a dimer. The active site cysteine was identified by site-directed mutagenesis. The expressed enzyme was purified and crystallized, facilitating its future analysis by X-ray crystallography.
Medications and substances of abuse
Published in James W. Albers, Stanley Berent, Neurobehavioral Toxicology: Neurological and Neuropsychological Perspectives, 2005
James W. Albers, Stanley Berent
A dose–response relationship exists between use of l-tryptophan and development of EMS. Paradoxically, the greatest neurologic impairment sometimes develops several months after discontinuing l-tryptophan, a finding very unusual for most neurotoxic syndromes. Epidemiological investigations implicated EMS to l-tryptophan produced by a single company using a recently developed strain of Bacillus amyloliquefaciens (Belongia et al., 1990). It was hypothesized that impurities in the product, consisting of a novel form of tryptophan, contributed to the toxicity. Studies of the product using high-performance liquid chromatography demonstrated an abnormal absorbance peak (peak E). This abnormality was thought to represent a novel amino acid contaminant that potentially contributed to the pathogenesis of EMS or acted as a surrogate for another chemical that induces the syndrome (Belongia et al., 1990). Recognition of the manufacturing defect resulted in discontinuation of the process, as well as in decreased use of l-tryptophan overall. Subsequently, EMS has essentially disappeared after the initial case reports.
Fibrinolytic Enzymes for Thrombolytic Therapy
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Swaroop S. Kumar, Sabu Abdulhameed
Most of the bacterial producers belong to the genus Bacillus and nattokinase isolated from Bacillus sp. turned to be the most prospective fibrinolytic enzyme among them. Nattokinase was initially isolated from Bacillus subtilis natto (Sumi et al., 1987). Various other bacterial strains were also reported to produce nattokinase enzyme and it will be discussed separately later. Apart from Nattokinase several other fibrinolytic enzymes were isolated from Bacillus sp. Subtilisin QK1 and subtilisin QK2 are two serine fibrinolytic proteases having a molecular weight of 42 and 28 kDa, respectively, isolated from B. subtilis QK02 (Ko et al., 2004). Bafibrinase, a thrombolytic enzyme of 32.3 kDa is produced by Bacillus sp. strain AS-S20-I (Mukherjee et al., 2012) and a 31 kDa thrombolytic enzyme is produced by B. subtilis BK-17 (Jeong et al., 2001). Subtilisin BSF1 from Bacillus subtilis A26 and BAF1 produced by Bacillus amyloliquefaciens An6 are two serine proteases with molecular weight of 28 and 30 kDa, respectively, both having fibrinolytic potential (Agrebi et al., 2009, 2010). Thrombolytic activity along with plasminogen activation was exhibited by two proteolytic enzymes having molecular weight 29 and 29.5 kDa, produced by Bacillus halodurans IND18 and Bacillus cereus IND1, respectively (Vijayaraghavan et al., 2016b; Vijayaraghavan and Vincent, 2014). A 20.5 kDa metalloprotease was purified from Bacillus subtilis K42 which also showed fibrinolytic as well as anticoagulant potential (Hassanein et al., 2011). URAK enzyme produced by Bacillus cereus NK1 [Deepak et al., 2010] and bacillopeptidase DJ-2 (bpDJ-2) from Bacillus sp. DJ-2 are two other thrombolytic enzymes from the Bacillus species (Choi et al., 2005). A few fibrinolytic enzymes with their properties are summarized in Table 4.5.
Insights in nodule-inhabiting plant growth promoting bacteria and their ability to stimulate Vicia faba growth
Published in Egyptian Journal of Basic and Applied Sciences, 2022
Amr M. Mowafy, Mona S. Agha, Samia A. Haroun, Mohamed A. Abbas, Mohamed Elbalkini
The isolate P3 obtained in this study, which is phylogenetically very close to Bacillus amyloliquefaciens, was found to be an IAA producer in addition to its ability to produce ammonia, HCN, siderophores, amylase, cellulase protease, and lipase. Additionally, it could sequestrate for its ability to produce siderophores. Bacillus amyloliquefaciens that is belonging to firmicutes is famous for its activity as plant growth promoting rhizobacteria. It has been reported that B. amyloliquefaciens can produce IAA and GA3 [31]. Additionally, it is considered as a potential biocontrol agent against several plant pathogens, such as Fusarium oxysporum [31] because of its ability to produce several volatile organic compounds (VOCs).
Microbially-derived cocktail of carbohydrases as an anti-biofouling agents: a ‘green approach’
Published in Biofouling, 2022
Harmanpreet Kaur, Arashdeep Kaur, Sanjeev Kumar Soni, Praveen Rishi
Amylases or amylolytic enzymes are glycoside hydrolases involved in the hydrolysis of starch, related oligo- and polysaccharides (Pandey et al. 2000). Amylases find numerous applications in various industrial processes, such as starch liquefaction (Nigam and Singh 1995), fermentation, and are employed in sugar, paper, and pharmaceutical industries. α-amylase is a hydrolytic enzyme and a renowned biofilm inhibitor that hydrolyze α-1,4 glycosidic bonds in amylose and amylopectin polymers, releasing monomers like glucose and maltose (Zhang et al. 2017). The enzyme is available commercially from several sources, including plants (barley and rice), animals, and microorganisms. Fungal sources of α-amylase are mainly restricted to Aspergillus species, for instance, Aspergillus oryzae, Aspergillus awamori, Aspergillus niger, among others. Bacillus amyloliquefaciens and Bacillus licheniformis are widely used bacterial species for large-scale production of α-amylase (Sivaramakrishnan et al. 2006). Several studies have brought attention to the antibiofilm potential of α-amylase. For instance, Craigen et al. (2011) investigated and observed that the specificity of α-amylase depends on the microorganism as it was able to reduce the biofilms of S. aureus and was not effective against the PNAG-rich biofilms of S. epidermidis. Another study was conducted by Kalpana et al. (2012) to decipher the antibiofilm activity of α-amylase extracted from B. subtilis S8-18. The results revealed that the application of α-amylase restricted biofilm formation and disrupted well-established biofilms of methicillin-resistant S. aureus (MRSA), V. cholerae, and P. aeruginosa. Likewise, the complete inhibition of biofilm formation by P. aeruginosa and S. aureus was observed on glass surfaces treated with α-amylase (Vaikundamoorthy et al. 2018). These studies suggest that α-amylase can achieve many clinical and industrial applications as an effective antibiofilm agent.
Egg extract of apple snail for eco-friendly synthesis of silver nanoparticles and their antibacterial activity
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Ratima Janthima, Arunrat Khamhaengpol, Sineenat Siri
With a high demand, many synthesis approaches of AgNPs have been reported. The most common methods for producing AgNPs are chemical and physical methods, such as evaporation-condensation, laser ablation, chemical reduction, electrochemical techniques, photoinduced reduction, UV-initiated photoreduction, irradiation methods and microemulsion techniques [4]. In general, conventional physical methods usually require high energy and often produce a low yield. Although a high production of nanoparticles can be obtained by chemical methods, they often use hazard chemicals and produce toxic by-products [5]. For these reasons, a biosynthesis of AgNPs has received increasing interest due to their simple, eco-friendly, non-toxic, and cost-effective processes. The biosynthesis of AgNPs can be mainly divided into two groups; in vivo and in vitro syntheses. For in vivo synthesis, living organisms are used as biofactories to produce metallic nanoparticles by enzymatic processes inside the cells; fungus (Aspergillus flavus) [6], bacteria (Corynebacterium strain SH09) [7]. For in vitro synthesis, a formation of AgNPs is facilitated via a use of biomolecules and other substances extracted from bacteria [8], fungi [9], yeasts [10], plants [11], and algae [12] as reducing and stabilizing agents. In addition, the secreted proteins and enzymes in the cultures of Bacillus amyloliquefaciens, Bacillus subtilis, Aeromonas sp. THG-FG1.2, and Weissella oryzae DC6 were also reported to facilitate the formation of AgNPs [13–15]. Among in vitro syntheses, most reports focused on using plant extracts to facilitate a production of AgNPs. The extracts derived from various species and parts of plants were used for green syntheses of AgNPs, such as arabica coffee seeds (Coffea Arabica) [16], papaya fruit (Carica papaya) [17], Asian bushbeech leaves (Gmelina asiatica) [18], and ginseng leaves (Panax ginseng) [19]. The main components in plant extracts that might function as reducing agents to reduce Ag+ to Ag0 are proteins, amino acids, organic acid, vitamins, flavonoids, alkaloids, polyphenols, terpenoids, and polysaccharides [20]. As compared with plant extracts, the extracts of crustacean eggs are one of the interesting sources of reducing and stabilizing agents due to their abundant availability, low cost, high protein content, and available chromophores [21], potentially function as reducing and stabilizing agents. However, there has been no report on using the extracts of crustacean eggs for a green synthesis of AgNPs.