Enzymes of SPZ7 phage: Isolation and properties

Abstract

Bacteriophage enzyme preparations exolysin and endolysin were studied. Exolysin (a phage-associated enzyme) was obtained from tail fraction and endolysin from phage-free cytoplasmic fraction of disintegrated Salmonella enteritidis cells. A new method for purification of these enzymes was developed, and their molecular masses were determined. The main catalytic properties of the studied enzymes (pH optimum and specificity to bacterial substrates) were found to be similar. Both enzymes lyse Escherichia coli cells like chicken egg lysozyme, but more efficiently lyse S. enteritidis cells and cannot lyse Micrococcus luteus, a good substrate for chicken egg lysozyme. Similar properties of exolysin and endolysin suggest that these enzymes are structurally similar or even identical.

Bacteriolytic enzymes from the blood plasma of the sheep

“…This fact may be explained by the presence of hydrophobic regions on the protein surface, which leads to the nonproductive sorption of the enzyme on substrate cells as the ionic strength increases. In the case of M34EM, the fall in the lysis rate with increas ing ionic strength of buffer is insignificant, and the picture is on the whole similar to that observed earlier for chicken egg lysozyme [7,9].…”

“…Bacteriolytic activity of protein factors in fractions after the chromatographic separation was determined by the turbidimetric method at 650 nm at 37°C [7,9,11] using E. coli, M. luteus, and B. subtilis cells as sub strates. The activity is expressed in conventional units (c.u.)…”

“…This substantially restricts the possibilities for studying the 1 properties of enzymes able to lyse bacterial cells. In recent years, novel approaches to the description of these complex systems have been developed [7,[9][10][11], which opens up further opportunities for the detection and characterization of these enzymes in living sys tems, in particular, the blood plasma of animals. Detailed investigations of the properties of bacteri olytic factors of animals are of current interest for understanding various aspects of the functioning of the immune system and the design of novel drugs.…”

Bacteriolytic Activity Of Human Interleukin-2, Chicken Egg Lysozyme In The Presence Of Potential Effectors

“…These peptide antibiotics are known cytostatics for E.coli [14, 15]: hence, the similarity in the observed effects may originate from their direct action on the cells and not from a modulation of the properties of bacteriolytic factors. The antibiotic by itself cannot cause cell lysis but renders a cell more sensitive to bacteriolytic enzymes, as was observed for endolysine from bacteriohages [16]. …”