Irreversible enzyme inhibitors. CLXVIII. Irreversible inhibition of dihydrofolate reductase and cell wall transport by pyrimidines and dihydro-s-triazines with pyridinium side chains

1970 ◽  
Vol 13 (2) ◽  
pp. 280-284 ◽  
Author(s):  
Bernard Randall. Baker ◽  
Nicolaas M. J. Vermeulen ◽  
Adrian J. Ryan
Keyword(s):  
Cell Wall ◽  
Dihydrofolate Reductase ◽  
Enzyme Inhibitors ◽  
Side Chains ◽  
Irreversible Inhibition

Cephalothin v. cephaloridine

1969 ◽  
Vol 7 (26) ◽  
pp. 101-102
Keyword(s):  
Cell Wall ◽  
Side Chains ◽  
Cell Wall Synthesis

Cephalosporin compounds, like the penicillins, act by inhibiting cell wall synthesis in multiplying bacteria. By attaching different side chains to the 7-aminocephalosporanic acid nucleus, a number of different cephalosporins have been produced. The first drug of the group to be introduced in Britain was cephaloridine (Ceporin - Glaxo), which we discussed in 1965.1 Now another compound, cephalothin (Keflin - Lilly) has become available. It has been used in the U.S.A. since 1963, and much of the information about it comes from American work. Very recently a third cephalosporin has been introduced, cephalexin (Ceporex - Glaxo; Keflex - Lilly). Its most important feature is that it is active by mouth. We shall discuss it in a forthcoming issue.

Distribution of antigenic oligomannosyl side chains in the cell wall mannans of several strains of Candida tropicalis

2003 ◽  
Vol 180 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Hidemitsu Kobayashi ◽  
Hiroko Oyamada ◽  
Kyoko Matsuda ◽  
Nobuyuki Shibata ◽  
Shigeo Suzuki
Keyword(s):  
Cell Wall ◽  
Candida Tropicalis ◽  
Side Chains

Irreversible enzyme inhibitors. CLXXV. Irreversible inhibition of purifed dihydrofolic reductase

1970 ◽  
Vol 13 (6) ◽  
pp. 1143-1148 ◽  
Author(s):  
Bernard Randall Baker ◽  
Nicolaas M. J. Vermeulen
Keyword(s):  
Enzyme Inhibitors ◽  
Irreversible Inhibition

scholarly journals Pectin Rhamnogalacturonan II: On the “Small Stem with Four Branches” in the Primary Cell Walls of Plants

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Beda M. Yapo
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Vascular Plants ◽  
Minor Component ◽  
Primary Cell ◽  
Side Chains ◽  
Complex Cell ◽  
Rhamnogalacturonan Ii ◽  
Branching Point ◽  
A Chain

Rhamnogalacturonan II (RG-II) is a type of block copolymer of complex pectins that represents a quantitatively minor component of the primary cell walls of land (vascular) plants. The structural composition of RG-II is almost totally sequenced and appears to be remarkably conserved in all tracheophytes so far examined. The backbone of RG-II, released from complex (cell wall) pectins by endo-polygalacturonase (Endo-PG) treatment, has been found to contain up to 15 (1→4)-linked-α-D-GalpA units, some of which carry four well-defined side chains, often referred to as A-, B-, C-, and D-side chains. Nevertheless, the relative locations on the backbone of these four branches, especially the A chain, remain to be ascertained. A combination of different data suggests that neither the terminal nonreducing GalA nor the contiguous GalA unit is likely to be the branching point of the A chain, but probably the ninth GalA residue from the reducing end, assuming a minimum backbone length of 11 (1→4)-linked-α-d-GalpA. The latest reports on RG-II are here highlighted, with a provided update for the macrostructure and array of functionalities.

Cell wall disassembly in ripening fruit

2006 ◽  
Vol 33 (2) ◽  
pp. 103 ◽  
Author(s):  
David A. Brummell
Keyword(s):  
Cell Wall ◽  
Middle Lamella ◽  
Primary Cell Wall ◽  
Side Chains ◽  
Fruit Softening ◽  
Structure Degradation ◽  
Wide Range ◽  
Textural Changes ◽  
Cell Wall Disassembly ◽  
Pectin Solubilisation

Fruit softening during ripening involves a coordinated series of modifications to the polysaccharide components of the primary cell wall and middle lamella, resulting in a weakening of the structure. Degradation of polysaccharides and alterations in the bonding between polymers cause an increase in cell separation and a softening and swelling of the wall, which, combined with alterations in turgor, bring about fruit softening and textural changes. A wide range in the extent of cell wall pectic modifications has been observed between species, whereas the depolymerisation of xyloglucan is relatively limited and more consistent. The earliest events to be initiated are usually a loss of pectic galactan side chains and the depolymerisation of matrix glycans, which may begin before ripening, followed by a loss of pectic arabinan side chains and pectin solubilisation. The depolymerisation of pectins may begin during early to mid-ripening, but is usually most pronounced late in ripening. However, some of these events may be absent or occur at very low levels in some species. Cell wall swelling may be related to a loosening of the xyloglucan–cellulose network and to pectin solubilisation, and these processes combined with the loss of pectic side chains increase wall porosity. An increase in wall porosity later in ripening may allow increased access of degradative enzymes to their substrates.

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