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Yeast as Source for Therapeutic and Diagnostic Proteins
Published in Yoshikatsu Murooka, Tadayuki Imanaka, Recombinant Microbes for Industrial and Agricultural Applications, 2020
Annie De Baetselier-Van Broekhoven
Lysozyme is the common name given to those enzymes, commonly occurring in nature, that are known to catalyze the hydrolysis of the β-1,4-glycosidic bond between TV-acetylmuramic acid and N-acetylglucosamine in the bacterial peptidoglycan. Recently, this enzyme has gained considerable interest not only for its structure-function relationship, but also for its potential applications in the health care industry. In addition to its antibacterial action, data support the view that lysozyme may have analgesic [35], antitumor [36], antimetastatic [37], and anti-inflammatory activities [38]. Chicken lysozyme is already used in the pharmaceutical industry as an antibacterial and antiinflammatory drug. For medical applications, human lysozyme may be preferable to chicken lysozyme because of reduced allergic side effects. However, unlike chicken lysozyme, for which an abundant source exists and is currently exploited (i.e., egg white), human lysozyme cannot be provided in large quantities for commercial purposes.
Electrospraying and Spinning Techniques
Published in C. Anandharamakrishnan, S. Parthasarathi, Food Nanotechnology, 2019
Maria Leena, K.S. Yoha, J.A. Moses, C. Anandharamakrishnan
In a study by Li et al., lysozyme was effectively immobilized in nanofiber matrix to protect its activity. Lysozyme is a positively charged antibacterial enzyme able to hydrolyze the peptidoglycan layer of the cell wall of some gram-positive bacteria and used as bacterial inhibitor in food packaging food preservation applications. However, it lacks stability. A mixture of lysozyme and rectorite was electrosprayed on negatively charged cellulose acetate nanofibers and immobilized. Rectorite was added to control the release rate of enzymes from the nanofibers. Here the enzyme was entrapped in semi-permeable nanofibers support material, thus immobilizing it while allowing substrates, co-factor and products to pass through the membrane. This process is proposed as a method to overcome issues with recovery and reuse of enzymes and also to increase the long term stability of the enzymes for industrial applications (Li et al., 2014b).
Enzyme Catalysis
Published in Harvey W. Blanch, Douglas S. Clark, Biochemical Engineering, 1997
Harvey W. Blanch, Douglas S. Clark
Ahern and Klibanov (Science 228,1280 (1985)) examined the factors leading to the irreversible thermal deactivation of hen egg-white lysozyme. Lysozyme is a small monomeric enzyme (MWt 14,500) which is well characterized; it catalyzes the hydrolysis of bacterial cell walls by breaking the polysaccharide component which consists of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), linked β-1,4. The substrate binds in a cleft which has six sites, designated A,B,C,D,E and F. NAM residues can only bind in the B, D and F sites, whereas NAG can bind at all sites. Bond cleavage occurs between sites D and E.
Purification and characterization of lysozyme from Chinese Lueyang black-bone Silky fowl egg white
Published in Preparative Biochemistry and Biotechnology, 2019
Chen Chen, Xinxin Li, Lijuan Yue, Xian Jing, Yiqi Yang, Youmei Xu, Sanqiao Wu, Yinku Liang, Xiang Liu, Xiaoying Zhang
The main function of lysozyme, also known as N-acetyl-muramic-hydrolase, is as a glycoside hydrolytic enzyme which cleaves the β-1,4-glycosidic linkage between N-acetyl muramic acid and N-acetyl glucosamine (GlcNAc) of peptidoglycans in Gram-positive bacterial cell walls.[4] A critical role of lysozyme is to protect against bacterial, viral, and fungal infections. As an antimicrobial protein, lysozyme can kill some Gram-positive bacteria, but is ineffective against Gram-negative bacteria.[5,6] Because lysozymes have antibacterial properties and complement system-modulating activities, they are widely used in the food processing field to keep food fresh and for food storage, in animal feeding, and in the medical health field to treat ulcers and infections or as a replacement for antibiotics. Therefore, the food industry, the animal breeding industry, and the prevention and treatment of disease demand large amounts of lysozyme.[7] Worldwide, it is estimated that over 100 tons of lysozyme are used commercially each year.[8] Lysozyme with high purity, high activity and low cost has been attracting great attention in food and medicinal industries.[9] The conventional enrichment methods for lysozyme from egg white are salt precipitation, centrifugation, ultra-filtration, adsorption chromatography and ion-exchange chromatography.[10] In addition, affinity membrane chromatography[11] and dye-ligand chromatography[12] was developed, for the lysozyme purification. In large-scale production, conventional enrichment medium of lysozyme method suggested as cost effective and it is widely applied in the industries.