Microbial Cell Walls and Membranes. Questo articolo non è disponibile.Microbial Cell Walls and Membranes

In 1968 when Cell Walls and Membranes was published it was still reasonable to attempt to write a book covering the whole subject. Accordingly this edition of the book had something to say about walls from micro-organisms and plants as well as about membranes from bacteria and animal cells. A decade later this is manifestly impossible. Knowledge about almost all the subjects has grown explosively, par­ ticularly about membranes and the biosynthesis of macromolecules. Moreover aspects of the subject that were still in a relatively primitive state ten years ago have grown into highly sophisticated subjects worthy of extended treatment. The result is that the present book has had to be confined to structures and functions relating to only one division of the biological kingdom, namely micro-organisms. Even then severe limitations have had to be made to keep the task within the time available to the authors and their expertise. A few of the titles of chapters such as those on the isolation of walls and membranes, the structure of the components of bacterial and micro-fungal walls and their biosynthesis remain from the earlier book. These chapters have been almost completely rewritten and a number of quite new chapters added on topics such as the action of the antibiotics that inhibit bacterial wall syn­ thesis, on the function of bacterial membranes, and the bacterial autolysins.

1 Ultrastructure of bacterial envelopes.- 1.1 Introduction.- 1.2 The Gram-positive cell wall.- 1.3 The Gram-negative cell wall.- 1.4 Membrane morphology.- 1.5 Internal membranes.- 1.6 Specialized membrane systems.- References.- 2 Isolation of walls and membranes.- 2.1 Introduction.- 2.2 Isolation of walls and membranes from Gram-positive species.- 2.3 Separation of the components of the wall from Gram-negative species.- 2.4 Preparation of specialized intracytoplasmic membranes.- References.- 3 Membrane structure and composition in micro-organisms.- 3.1 General ideas of membrane structure.- 3.2 Some physical properties of membranes.- 3.3 Composition of microbial membranes.- 3.4 Proteins in membranes.- References.- 4 Membrane functions.- 4.1 Active components and functions of bacterial cell walls.- 4.2 Functions of the cytoplasmic membrane.- 4.3 Components of the electron transport chain.- 4.4 The coupling of energy flow to phosphorylation.- 4.5 Isolation and properties of Mg2+-Ca2+ ATPase.- 4.6 Vesiculation of membranes.- 4.7 Transport of metabolites and ions.- 4.8 Binding proteins.- 4.9 Mesosomal membrane.- 4.10 Outer membrane of Gram-negative bacteria.- References.- 5 Membranes of bacteria lacking peptidoglycan.- 5.1 Introduction.- 5.2 Mycoplasmas.- 5.3 Extreme halophiles.- 5.4 Bacterial L-forms.- References.- 6 Structure of peptidoglycan.- 6.1 Introduction.- 6.2 Modification of the basic peptidoglycan structure.- 6.3 Three-dimensional structure of peptidoglycans.- 6.4 Cell walls of prokaryotes without peptidoglycan.- References.- 7 Additional polymers in bacterial walls.- 7.1 Gram-positive bacteria.- 7.2 Gram-negative bacteria.- References.- 8 Biosynthesis of peptidoglycan.- 8.1 Introduction.- 8.2 Synthesis of nucleotide sugar precursors.- 8.3 The lipid cycle.- 8.4 Formation of cross-bridge peptides.- 8.5 Polymerization of disaccharide-peptide units.- 8.6 Transpeptidation: The formation of cross-links.- 8.7 D-Alanine carboxypeptidases.- References.- 9 Antibiotics affecting bacterial wall synthesis.- 9.1 Introduction.- 9.2 Phosphonomycin (Fosfomycin).- 9.3 Antibiotics inhibiting D-alanine metabolism in peptidoglycan biosynthesis: cycloserine, O-carbamoyl-D-serine, alaphosphin (L-alanyl-L-1-aminoethyl phosphonic acid) and the haloalanines.- 9.4 Bacitracin.- 9.5 Tunicamycin.- 9.6 The vancomycin group of antibiotics: vancomycin, ristocetins, ristomycins, actinoidin.- 9.7 ?-Lactam antibiotics: the penicillins and cephalosporins.- 9.8 Antibiotics inhibiting biosynthesis of wall polymers but whose site of action is not yet established.- References.- 10 Biosynthesis of other bacterial wall components.- 10.1 Biosynthesis of teichoic acids.- 10.2 Biosynthesis of other components of the Gram-positive bacterial wall.- 10.3 Biosynthesis of the lipopolysaccharides.- 10.4 Iipoprotein from the outer membrane of Gram-negative bacteria.- References.- 11 The bacterial autolysins.- 11.1 Introduction.- 11.2 Bond specificity and distribution of bacterial autolysins.- 11.3 Purification and properties of the autolytic enzymes.- 11.4 Location of autolytic enzymes.- 11.5 Function of autolysins.- References.- 12 Cell walls of Mycobacteria.- 12.1 Wall composition.- 12.2 Adjuvant and other immunostimulant properties.- 12.3 Antitumour activity.- References.- 13 Cell walls of filamentous fungi.- 13.1 Introduction.- 13.2 Carbohydrates in the wall.- 13.3 Wall composition and dimorphism.- 13.4 Melanins and depsipeptides.- 13.5 Conclusion.- References.- 14 Biosynthesis of wall components in yeast and filamentous fungi.- 14.1 Introduction.- 14.2 Biosynthesis of chitin.- 14.3 Biosynthesis of mannan.- 14.4 Biosynthesis of glucan.- References.- 15 The cell wall in the growth and cell division of bacteria.- 15.1 Introduction.- 15.2 Growth of streptococcal cell walls.- 15.3 Growth of the walls of Gram-positive rod-shaped bacteria.- 15.4 Growth of the Gram-negative cell wall.- 15.5 Growth of cytoplasmic membranes.- 15.6 Mutants with disturbed surface growth.- 15.7 Helical growth of bacteria.- References.