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Bioactive Proteins and Peptides from Agro-Industrial Waste
Published in Anil Kumar Anal, Parmjit S. Panesar, Valorization of Agro-Industrial Byproducts, 2023
Nuntarat Boonlao, Thatchajaree Mala, Sushil Koirala, Anil Kumar Anal
Antimicrobial peptides are usually small (containing 20–46 amino acids), basic (mostly containing lysine and arginine), and amphipathic (Toldrá et al., 2018). They are mostly rich in hydrophobic amino acids, including valine, tryptophan, phenylalanine, leucine, and isoleucine. These peptides consist of cationic amino acids, which possess a net positive charge between +2 and +9 (Haney and Hancock, 2013). Antimicrobial peptides can fight several pathogenic micro-organisms, including bacteria, fungi, and viruses (Treffers et al., 2005). Antimicrobial peptides act against pathogenic micro-organisms via the electrostatic interaction of peptides and their cell membrane (Figure 7.2). Antimicrobial peptides with a positive charge initially act on anionic lipids located on the membrane surface. The peptide is then infused with the lipid bilayer of the cell membrane, resulting in the replacement of lipids (Fjell et al., 2012). The ability of antimicrobial peptides to disrupt microbial cells can be achieved by forming ion channels or transmembrane pores. This leads to an imbalance of cellular contents, thereby modulating the process of replication, transcription, and translation of the DNA sequence via binding to specific intracellular targets, hindering the multiplication and growth of microbial cells (Zhao et al., 2012).
Biodegradable Eco-Friendly Packaging and Coatings Incorporated of Natural Active Compounds
Published in Sanjay Mavinkere Rangappa, Parameswaranpillai Jyotishkumar, Senthil Muthu Kumar Thiagamani, Senthilkumar Krishnasamy, Suchart Siengchin, Food Packaging, 2020
Josemar Gonçalves de Oliveira-Filho, Ailton Cesar Lemes, Anna Rafaela Cavalcante Braga, Mariana Buranelo Egea
The mechanism of action of antimicrobial peptides usually involves changes in biological membranes. Initially, there is an electrostatic attraction between the peptide molecules, usually positively charged, and the anionic lipids found on the surface of the microbial plasma membrane. Then, due to the amphipathic structure of these peptides, the interaction between the peptides and the membrane surface occurs, with subsequent structural degradation of the plasma membrane through the formation of ion channels or by the production of transmembrane pores. This process causes an imbalance of cellular contents, thereby deregulating the process of replication, transcription, and translation of the DNA sequence by binding to specific intracellular targets, preventing the multiplication and growth of microbial cells (Naghmouchi et al., 2007; Zhao et al., 2012).
Synthesis of Bioactive Peptides for Pharmaceutical Applications
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Jaison Jeevanandam, Ashish Kumar Solanki, Shailza Sharma, Prabir Kumar Kulabhusan, Sapna Pahil, Michael K. Danquah
Recently, bioactive peptides of animals, plants, and microorganism origins are significantly utilized in the treatment and prevention of cardiovascular diseases, cancer and infections (Cicero et al., 2017). Likewise, antimicrobial peptides with enhanced bioactivity are used to inhibit the growth of harmful microbes and prevent the widespread of their associated diseases (Haney et al., 2017). Hence, researchers are utilizing bioactive peptides as an alternate to conventional pharmaceutical entities to develop peptide-based treatment approaches. Thus, the current chapter is an overview of current synthesis methods that are used to synthesize bioactive peptides as they are the determining factor that elevates their bioactivity. Further, the procedures employed for the refinement, characterization and formulation of bioactive peptides in recent times and their pharmaceutical applications are also presented. Additionally, the existing challenges and the bioactive peptides in the future of pharmaceutical industry are also discussed.
Studies on a new antimicrobial peptide from Vibrio proteolyticus MT110
Published in Preparative Biochemistry & Biotechnology, 2023
Himanshu Verma, Kanti N. Mihooliya, Jitender Nandal, Debendra K. Sahoo
The widespread use of broad-spectrum medicines in recent years has resulted in the global spread of antibiotic-resistant bacteria. Due to their low antimicrobial resistance generated by increased hydropathicity and absence of cross-resistance between species, antimicrobial peptides have already shown potential as a more effective alternative to these traditional antibiotics.[28,29] Another application of these antimicrobial peptides could be their use as bio-preservatives in foods and beverages, as chemical preservatives such as nitrates and sulfites are known to have harmful effects on human health.[30] However, antimicrobial peptides for the above-said applications should have requisite physicochemical properties. Indian marine environment harbors rich biodiversity, and in our continuous search for new antimicrobial peptides, the marine samples collected from the Indian coast were screened.
Functional expression, purification, and antimicrobial activity of a novel antimicrobial peptide MLH in Escherichia coli
Published in Preparative Biochemistry and Biotechnology, 2018
Guo-Li Gong, Yuan Wei, Zhong-Zhong Wang
Antimicrobial peptides (AMPs) are small molecular polypeptides that widely exist in natural organisms and are major components for bio-immune system.[123] Multidrug-resistant bacterial infections have emerged as one of the world’s greatest health threats.[4] With the increasing exacerbation of antibiotics’ overuse, more and more antibiotic-resistant bacterial strains have emerged. Most AMPs are effective and active against bacteria, fungi, and virus.amPs are effective at low micromolar concentrations against a broad range of microorganisms, and in many cases including those resistant to conventional antibiotics.[4,5] AMPs are considered one of the promising alternatives to antibiotics due to its broad antimicrobial spectrum, stable physical and chemical properties and difficult for target bacteria to develop resistance, and therefore bearing a wide prospect in medicine, food, and agriculture.[6,7] However, natural antibacterial peptides are hard to be extracted and always leading to a high cost and low efficiency. Recent studies found that new heterozygous antimicrobial peptides synthesized from at least two kinds of antimicrobial peptides can overcome the weaknesses of natural antimicrobial peptides and showed increased antimicrobial effects. Therefore, synthesized heterozygous peptides will be the promising sources to develop AMPs for potential therapeutics.
Antimicrobial activities of amphiphilic cationic polymers and their efficacy of combination with novobiocin
Published in Journal of Biomaterials Science, Polymer Edition, 2022
Atsushi Miyagawa, Shinya Ohno, Tomohiko Hattori, Hatsuo Yamamura
Since the 1940s, many antimicrobial drugs have been developed [1–6]. Drug-resistant bacteria have also been detected since the 1940s, and this creates an urgent need for new antimicrobial drugs. The drug resistance of bacteria is caused by the overuse of antimicrobial drugs. Drug resistance is determined by the environmental load in which the drugs are used as well as the gene changes that occur during the short life of pathogenic organisms. Many drug-resistant bacteria, such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci, which are responsible for hospital-acquired infections, have currently become a critical problem [7–10]. Among the antibiotics being explored to deal with these bacteria, antimicrobial peptides (AMPs) have attracted considerable attention owing to their antimicrobial mechanism, which disrupts the cell membrane. The structural characteristics of AMPs include hydrophobic groups, such as alkyl and aryl groups, and hydrophilic groups, such as hydroxy and amino groups [11–14]. Therefore, AMPs show bifacial amphiphilicity because they contain both a hydrophobic side and a hydrophilic side. Since bacterial membranes involve negatively charged phospholipids, the cationic AMPs bind to the bacterial membranes via electrostatic interactions and disrupt them. They cause the breakdown of the transmembrane potential, which leads to the leakage of cytoplasmic components and eventually cell death. Thus, while bacteria often undergo mutation, it is difficult to change the structure of the cell membrane, which serves as the skeleton of cells and to acquire resistance against this antimicrobial mechanism [15–19].