scholarly journals Structure of the cell wall of lactobacilli. Role of muramic acid phosphate in Lactobacillus fermenti

1968 ◽  
Vol 108 (3) ◽  
pp. 363-368 ◽  
Author(s):  
K. W. Knox ◽  
Klara J. Holmwood
Keyword(s):  
Cell Wall ◽  
Inorganic Phosphate ◽  
Enzyme Preparation ◽  
Muramic Acid ◽  
Dilute Acid ◽  
Acid Phosphate ◽  
Mild Conditions ◽  
Phosphodiester Linkage ◽  
Soluble Cell

1. The polysaccharide and mucopeptide components of the cell wall of Lactobacillus fermenti, serological group F, were separated by mild conditions of acid hydrolysis; the polysaccharide was composed of glucose and galactose. 2. Soluble cell-wall products were isolated from cell wall lysed by lysozyme and a Streptomyces enzyme preparation. The lysozyme-dissolved fraction contained a greater proportion of mucopeptide. 3. The soluble preparations were heated in dilute acid to hydrolyse the linkage between the polysaccharide and mucopeptide components and then incubated with acid phosphatase. 4. Inorganic phosphate was released from products of Streptomyces enzyme action but not from products of lysozyme action. 5. The phosphate was shown to be present in the mucopeptide as muramic acid phosphate. It is concluded that in the intact wall polysaccharide is joined to muramic acid by a phosphodiester linkage.

The nuclear magnetic resonance determination of the conformation of saccharides bound in subsite D of lysozyme

1978 ◽  
Vol 56 (6) ◽  
pp. 624-629 ◽  
Author(s):  
Steven L. Patt ◽  
John H. Baldo ◽  
Kim Boekelheide ◽  
Gregg Weisz ◽  
Brian D. Sykes
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cell Wall ◽  
Magnetic Resonance ◽  
Dihedral Angle ◽  
Muramic Acid ◽  
Coupling Constant ◽  
Hydrolysis Of ◽  
Nuclear Magnetic

The binding of the trisaccharide (2-acetamido-2-deoxy-D-muramic acid)-β(1→4)-(2-aceta-mido-2-deoxy-D-glucosyl)-β(1→4)-(2-acetamido-2-deoxy-D-muramic acid) to subsites B, C, and D in lysozyme has been studied by 1H nuclear magnetic resonance methods. In particular, the coupling constant between H1 and H2 of the reducing saccharide bound in subsite D has been determined. The coupling constant for the bound saccharide indicates that the dihedral angle between C1 and C2 for the reducing saccharide is not significantly changed upon binding to lysozyme. This result is discussed in terms of other evidence for the role of distortion of the saccharide bound in subsite D in the lysozyme-catalyzed hydrolysis of cell wall oligosaccharides.

Role of bacterial cell wall proteinase in antihypertension

2002 ◽  
Vol 22 (1-2) ◽  
pp. 209-222 ◽  
Author(s):  
Bénédicte Flambard
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Bacterial Cell Wall

scholarly journals An R2R3-type myeloblastosis transcription factor MYB103 is involved in phosphorus remobilization

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Fangwei Yu ◽  
Shenyun Wang ◽  
Wei Zhang ◽  
Hong Wang ◽  
Li Yu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Abiotic Stresses ◽  
Myb Transcription Factor ◽  
Ethylene Signaling ◽  
Biotic And Abiotic Stresses ◽  
P Deficiency ◽  
P Concentration ◽  
Increased Sensitivity

Abstract The members of myeloblastosis transcription factor (MYB TF) family are involved in the regulation of biotic and abiotic stresses in plants. However, the role of MYB TF in phosphorus remobilization remains largely unexplored. In the present study, we show that an R2R3 type MYB transcription factor, MYB103, is involved in phosphorus (P) remobilization. MYB103 was remarkably induced by P deficiency in cabbage (Brassica oleracea var. capitata L.). As cabbage lacks the proper mutant for elucidating the mechanism of MYB103 in P deficiency, another member of the crucifer family, Arabidopsis thaliana was chosen for further study. The transcript of its homologue AtMYB103 was also elevated in response to P deficiency in A. thaliana, while disruption of AtMYB103 (myb103) exhibited increased sensitivity to P deficiency, accompanied with decreased tissue biomass and soluble P concentration. Furthermore, AtMYB103 was involved in the P reutilization from cell wall, as less P was released from the cell wall in myb103 than in wildtype, coinciding with the reduction of ethylene production. Taken together, our results uncover an important role of MYB103 in the P remobilization, presumably through ethylene signaling.

scholarly journals Differential Role of Threonine and Tyrosine Phosphorylation in the Activation and Activity of the Yeast MAPK Slt2

2021 ◽  
Vol 22 (3) ◽  
pp. 1110
Author(s):  
Gema González-Rubio ◽  
Ángela Sellers-Moya ◽  
Humberto Martín ◽  
María Molina
Keyword(s):  
Cell Wall ◽  
Biological Activity ◽  
Biological Significance ◽  
Mitogen Activated Protein Kinase ◽  
Activation Loop ◽  
High Increase ◽  
Dual Specificity ◽  
Mitogen Activated Protein ◽  
Full Activation

The Mitogen-Activated Protein Kinase (MAPK) Slt2 is central to signaling through the yeast Cell Wall Integrity (CWI) pathway. MAPKs are regulated by phosphorylation at both the threonine and tyrosine of the conserved TXY motif within the activation loop (T190/Y192 in Slt2). Since phosphorylation at both sites results in the full activation of MAPKs, signaling through MAPK pathways is monitored with antibodies that detect dually phosphorylated forms. However, most of these antibodies also recognize monophosphorylated species, whose relative abundance and functionality are diverse. By using different phosphospecific antibodies and phosphate-affinity (Phos-tag) analysis on distinct Slt2 mutants, we determined that Y192- and T190-monophosphorylated species coexist with biphosphorylated Slt2, although most of the Slt2 pool remains unphosphorylated following stress. Among the monophosphorylated forms, only T190 exhibited biological activity. Upon stimulation, Slt2 is first phosphorylated at Y192, mainly by the MAPKK Mkk1, and this phosphorylation is important for the subsequent T190 phosphorylation. Similarly, dephosphorylation of Slt2 by the Dual Specificity Phosphatase (DSP) Msg5 is ordered, with dephosphorylation of T190 depending on previous Y192 dephosphorylation. Whereas Y192 phosphorylation enhances the Slt2 catalytic activity, T190 is essential for this activity. The conserved T195 residue is also critical for Slt2 functionality. Mutations that abolish the activity of Slt2 result in a high increase in inactive Y192-monophosphorylated Slt2. The coexistence of different Slt2 phosphoforms with diverse biological significance highlights the importance of the precise detection of the Slt2 phosphorylation status.

scholarly journals Peptidogalactomannan from Histoplasma capsulatum yeast cell wall: role of the chemical structure in recognition and activation by peritoneal macrophages

2021 ◽  
Author(s):  
Giulia Maria Pires dos Santos ◽  
Gustavo Ramalho Cardoso dos Santos ◽  
Mariana Ingrid Dutra da Silva Xisto ◽  
Rodrigo Rollin-Pinheiro ◽  
Andréa Regina de Souza Baptista ◽  
...  
Keyword(s):  
Cell Wall ◽  
Yeast Cell ◽  
Chemical Structure ◽  
Histoplasma Capsulatum ◽  
Peritoneal Macrophages ◽  
Yeast Cell Wall

Unprecedentedly high efficiency for photocatalytic conversion of methane to methanol over Au–Pd/TiO2 – what is the role of each component in the system?

2021 ◽  
Author(s):  
Xiaojiao Cai ◽  
Siyuan Fang ◽  
Yun Hang Hu
Keyword(s):  
Methane Conversion ◽  
High Efficiency ◽  
Mild Conditions ◽  
Highly Efficient ◽  
System P ◽  
Conversion Of Methane

Direct and highly efficient methane conversion to methanol under mild conditions is achieved via photocatalysis over Au–Pd/TiO2.

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