The disruptive effect of lysozyme on the bacterial cell wall explored by an in-silico structural outlook

PRIMO, EMILIANO D.; OTERO, LISANDRO HORACIO; RUIZ, FRANCISCO; KLINKE, SEBASTIÁN; GIORDANO, WALTER

BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION

JOHN WILEY & SONS INC

Lugar: New York; Año: 2018 vol. 46 p. 83 - 90

1470-8175

p { margin-bottom: 0.25cm; line-height: 120%; }The bacterial cellwall, a structural unit of peptidoglycan polymer comprised of glycanstrands consisting of a repeating disaccharide motif[N-acetylglucosamine (NAG) and N-acetylmuramylpentapeptide (NAMpentapeptide)], encases bacteria and provides structural integrityand protection. Lysozymes are enzymes that break down the bacterialcell wall and disrupt the bacterial life cycle by cleaving thelinkage between the NAG and NAM carbohydrates. Lab exercises focused onthe effects of lysozyme on the bacterial cell wall are frequentlyincorporated in biochemistry classes designed for undergraduatestudents in diverse fields as biology,microbiology, chemistry, agronomy, medicine, and veterinary medicine.Such exercises typically do not include structural data. We describehere a sequence of computer tasksdesigned to illustrate and reinforce both physiological andstructural concepts involved in lysozymeeffects on thebacterial cell-wall structure. This lab class usually lasts 3.5hours. First, the instructor presents introductory concepts of thebacterial cell wall and the effect of lysozyme on its structure.Then, students are taught to use computer modeling tovisualize the three-dimensional structure of alysozyme in complex with bacterial cell-wall fragments. Finally,the lysozyme inhibitory effect on a bacterial culture is optionallyproposed as a simple microbiological assay. The computer labexercises described here give students arealistic understanding of the disruptive effect of lysozymeson the bacterial cell wall, a crucial component in bacterialsurvival.