Changes Induced by Pre-Fixation in Polycation Bacteriolysis and Surface Alterations Matching the Model of Wall Picnosis in Cell Lysis

Abstract

Pretreatments of B. subtilis and S. aureus cells with lower concentrations of fixative agents, led to modifications in bacteriolytic effect exerted by polyarginine and protamine: Glutaraldehyde blocked polycation bacteriolysis while formaldehyde and osmium tetroxide (OSO4) having no influence on polyarginine action, increased constantly the cell sensitivity to protamine in lower doses otherwise nonlytic; the sensitizing action also resulted in the extension of protamine bacteriolytic pattern including several staphylococcal strains; higher bacteriolytic doses of protamine were contrastively unable to lyse OSO4 prefixed cells and gave an inconstant lytic value with formaldehyde treated bacteria. With higher concentrations, OSO4 preserved intactly its sensitizing action while formaldehyde displayed a decrease in its ability to sensitize B. subtilis cells to the lytic effect of protamine. Scaning electron microscopy of polycation treated cells showed prelytic lesions as surface granulations, shape and size modifications and cell splits. The interpretation of the results in terms of intra-and intermolecular adducts accompanied by con­ formational changes in surface macromolecules is discussed. It is concluded that the results match the model of polycation bacteriolysis by wall multizonal picnosis leading to surface splits and thereby triggering cell-lysis.

Polycation-Bacterium Interactions and Wall Subunits as Endocytosis Factors. Topoisomeraselike Action of Basic Polypeptides Suggesting a 7th Class of Enzymes: The Stereases

“…Histone H I, which participates alone in chrom atin super-packing [8,9], caused wall polycationic condensation being lytic. Thus, in addition to the previous observations fl, 2] the results reported here appear to fit once more into the model of multizonal wall pycnosis in poly cation bacteriolysis and its mechanism analogy with chromatin DNA pycnosis.…”

“…The prim ary prelytic alterations observed by SEM (Fig. 2) consisted in globular surface bodies very sim ilar to those induced by polyarginine and protam ine [2]. Since the resulting globular structures might be form ed by interactions involving polyions, i.e., wall polyanionic polysac charides and exogenous polycation molecules, they were operationally designated as polionosomes (poly-ionosomes).…”

“…Since histone HI and protam ine have " learned" along the evolution scale to interact as monomers with poly anionic DNA, each o f them is able to condense zonally the cell wall and to induce cell lysis, as predicted by the model of multizonal wall pycnosis [1], However, their binding abilities in wall conden sations are lower than those of the synthetic polyca tions, which bind nonspecifically many proteins and natural structures [14], It seems that the evolutionary organization of histone and protam ine structures resulted in an absent or lower binding ability [13], these considerations being illustrated by the diversity of the natural polycations in their abilities to induce bacteriolysis. Taking into account the previous SEM exam ina tions [2], the natural origin of histone HI and other experimental conditions, only prelytic m ixtures of histone HI and B. subtillis cells were used in prepar ing SEM specimens. The prim ary prelytic alterations observed by SEM (Fig.…”

“…CaCl2 2 m ; acetate-saline (natrium acetate 40 m M , NaCl 150 m M , pH 5.6); glutaral dehyde 25% for electron microscopy; 0 s 0 4 1% prepared as described [2], All were stored at 4 °C. Separate polycation solutions 2 m g/m l in bidistilled water were kept in portions o f 2 ml at -10 °C and used within a 12-day interval.…”

“…Samples pretreated with 0 s 0 4 0.1% were com pleted with lysine rich histone 100 ng/m l and incu bated with shaking, according to the routine pre viously described [2], The exam ination o f SEM specimens was undertaken by using a TEM /SEM Philips Type EM 400 at 20 kV (Fig. 2).…”