scholarly journals DL-endopeptidases function as both cell wall hydrolases and poly-γ-glutamic acid hydrolases

Microbiology ◽  
2018 ◽  
Vol 164 (3) ◽  
pp. 277-286 ◽  
Author(s):  
Tatsuya Fukushima ◽  
Natsuki Uchida ◽  
Masatoshi Ide ◽  
Takeko Kodama ◽  
Junichi Sekiguchi
Keyword(s):  
Cell Wall ◽  
Glutamic Acid ◽  
Acid Hydrolases ◽  
Cell Wall Hydrolases

In vitro Action of Gastric Mucosal Lysosomal Enzymes on Intracellular Gastric Glycoproteins

1979 ◽  
Vol 34 (1-2) ◽  
pp. 90-95 ◽  
Author(s):  
Fouad M. Fouad ◽  
D. Waldron-Edward
Keyword(s):  
Cell Wall ◽  
Lysosomal Enzymes ◽  
Gastric Ulceration ◽  
Mucosal Cell ◽  
Gastric Lesions ◽  
Acid Hydrolases ◽  
Gastric Mucosal Cells ◽  
Mucosal Cells ◽  
Specific Increase

Abstract The results show that incubation of gastric mucosal cells from rat at pH ~4.5 or in the presence of aspirin is associated with a specific increase in the activity of some acid-hydrolases. Intracellular glycoproteins, isolated by non-degradative techniques from rat or dog fundic mucosal cells, were found to be potential bio-substrates for these acid-hydrolyses. This may suggest that cleavage of the carbohydrate moieties of the intracellular and mucosal cell wall glycoproteins is a fundamental step in the development of gastric ulceration. A model for gastric lesions is proposed and discussed in the light of the results obtained.

The Candida albicans pH-regulated KER1 gene encodes a lysine/glutamic-acid-rich plasma-membrane protein that is involved in cell aggregation

Microbiology ◽  
2004 ◽  
Vol 150 (8) ◽  
pp. 2641-2651 ◽  
Author(s):  
Amparo Galán ◽  
Manuel Casanova ◽  
Amelia Murgui ◽  
Donna M. MacCallum ◽  
Frank C. Odds ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Plasma Membrane ◽  
Glutamic Acid ◽  
Germ Tube ◽  
Cell Surface Hydrophobicity ◽  
Cell Aggregation ◽  
Surface Hydrophobicity ◽  
Amino Acid Sequences ◽  
Calcofluor White

Immunoscreening of a Candida albicans cDNA library with a polyclonal germ-tube-specific antibody (pAb anti-gt) resulted in the isolation of a gene encoding a lysine/glutamic-acid-rich protein, which was consequently designated KER1. The nucleotide and deduced amino acid sequences of this gene displayed no significant homology with any other known sequence. KER1 encodes a 134 kDa lysine (14·5 %)/glutamic acid (16·7 %) protein (Ker1p) that contains two potential transmembrane segments. KER1 was expressed in a pH-conditional manner, with maximal expression at alkaline pH and lower expression at pH 4·0, and was regulated by RIM101. A Δker1/Δker1 null mutant grew normally but was hyperflocculant under germ-tube-inducing conditions, yet this behaviour was also observed in stationary-phase cells grown under other incubation conditions. Western blotting analysis of different subcellular fractions, using as a probe a monospecific polyclonal antibody raised against a highly antigenic domain of Ker1p (pAb anti-Ker1p), revealed the presence of a 134 kDa band in the purified plasma-membrane fraction from the wild-type strain that was absent in the homologous preparation from Δker1/Δker1 mutant. The pattern of cell-wall protein and mannoprotein species released by digestion with β-glucanases, reactive towards pAbs anti-gt and anti-Ker1p, as well as against concanavalin A, was also different in the Δker1/Δker1 mutant. Mutant strains also displayed an increased cell-surface hydrophobicity and sensitivity to Congo red and Calcofluor white. Overall, these findings indicate that the mutant strain was affected in cell-wall composition and/or structure. The fact that the ker1 mutant had attenuated virulence in systemic mouse infections suggests that this surface protein is also important in host–fungus interactions.

Nutritional requirements for cell wall synthesis in Micrococcus lysodeikticus

1969 ◽  
Vol 15 (4) ◽  
pp. 327-334
Author(s):  
M. P. Hatton
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Glutamic Acid ◽  
Dry Weight ◽  
Defined Medium ◽  
Complete Medium ◽  
Magnesium Ions ◽  
Cell Wall Synthesis ◽  
Micrococcus Lysodeikticus ◽  
Total Dry Weight

Preferential cell wall synthesis in Micrococcus lysodeikticus, as determined by an increase in the dry weight of the cell wall, took place in a medium containing DL-glutamic acid, DL-alanine, L-lysine, glycine, magnesium ions, glucose and phosphate buffer, pH 7.0. Cell wall synthesis could not be completely dissociated from protein synthesis in the 'cell wall' medium. The cell wall synthesized in the defined medium accounted for 40–56% of the total dry weight increase of the cells. Chloramphenicol had no effect on cell wall synthesis. Incorporation of uracil and guanine in the medium did not result in any increase in the amount of cell wall synthesized. DL-Glutamic acid alone, or a mixture of the three amino acids DL-alanine, L-lysine, and glycine, were capable of replacing the four amino acids present in the complete medium, but under these conditions the total dry weight of cell wall synthesized was only 75% of that produced in the complete medium. There was no reduction in cell wall synthesis when L-glutamic acid replaced DL-glutamic acid, L-alanine replaced DL-alanine, or sucrose replaced glucose in the cell wall medium. Deprivation of magnesium ions produced the greatest decrease in wall synthesis; this was the most important single factor involved in cell wall synthesis which was studied in the present investigation. There was no observable change in the chemical composition of the cell wall synthesized in the 'wall' medium when compared to that synthesized by cells grown in a complex medium.

scholarly journals STUDIES ON THE CHEMICAL STRUCTURE OF THE STREPTOCOCCAL CELL WALL

1962 ◽  
Vol 115 (1) ◽  
pp. 49-62 ◽  
Author(s):  
Richard M. Krause ◽  
Maclyn McCarty
Keyword(s):  
Cell Wall ◽  
Glutamic Acid ◽  
Cell Walls ◽  
Soluble Group ◽  
Chemical Structure ◽  
Streptococcal Cell Wall ◽  
Whole Cell ◽  
Cell Wall Lysis ◽  
C Cell ◽  
Serological Studies

The trypsinized cell walls of Group C streptococci contain two components, the group-specific carbohydrate and a mucopeptide polymer. Hot formamide extraction of Group C cell walls results in a soluble group-specific carbohydrate fraction and an insoluble mucopeptide residue. This mucopeptide, similar in composition to that of Groups A and A-variant streptococci, contains N-acetylglucosamine, N-acetylmuramic acid, alanine, glutamic acid, lysine, and glycine. It is dissolved by the muralytic enzymes, including lysozyme, which does not attack the whole cell wall. Lysis of the cell wall by phage-associated lysin results in the release of soluble fragments composed of the elements of mucopeptide. Group C carbohydrate extracted with formamide is composed primarily of N-acetylgalactosamine and rhamnose. Serological studies suggest that the specificity of Group C carbohydrate is determined by the N-acetylgalactosamine.

Cytochemistry and ultrastructure of the dehiscence zone of almond (Prunus dulcis) fruits

1990 ◽  
Vol 68 (1) ◽  
pp. 63-72 ◽  
Author(s):  
K. Weis ◽  
V. S. Polito
Keyword(s):  
Cell Wall ◽  
Fusion Zone ◽  
Prunus Dulcis ◽  
Epidermal Cells ◽  
Sectioned Material ◽  
Discrete Band ◽  
Dehiscence Zone ◽  
Suture Fusion ◽  
Cell Wall Hydrolases ◽  
Original Line

At maturity, the almond pericarp dehisces along the ventral suture, a region that originates by fusion of epidermal cells and subsequently differentiates into a separation layer. We have characterized the ontogeny of the fusion–dehiscence zone with emphasis on cell wall characteristics by using cytochemical methods for detection of pectin, cutin, cellulose, and lignin to examine the middle lamellae and primary and secondary walls in dehiscence-zone cells. Carpel margins became united postgenitally along opposing epidermal layers giving rise to the suture. Fusion-zone cells host epidermal characteristics, elaborated broad pectinaceous walls, and ultimately formed a discrete band of cells that dehisced along the original line of fusion by dissolution of cell wall pectins. Treatment of treeborne fruits with 1 ppm ethylene gas or extraction of sectioned material with cell wall hydrolases resulted in cell wall changes similar to those in predehiscent fruits.

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