In vivo breakdown of dietary [methyl−14C] and [uronate-6−14C]pectin-labelled spinach cell walls by rat intestinal microorganisms and incorporation of14C into host tissues

1995 ◽  
Vol 68 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Callum J Buchanan ◽  
Stephen C Fry ◽  
Martin A Eastwood
Keyword(s):  
Cell Walls ◽  
Intestinal Microorganisms ◽  
Host Tissues

Varying influence of the autolysin, N-acetyl muramidase, and the cell envelope proteinase on the rate of autolysis of six commercial Lactococcus lactis cheese starter bacteria grown in milk

2000 ◽  
Vol 67 (4) ◽  
pp. 585-596 ◽  
Author(s):  
SELVARANI GOVINDASAMY-LUCEY ◽  
PRAMOD K. GOPAL ◽  
PATRICK A. SULLIVAN ◽  
CHRISTOPHER J. PILLIDGE
Keyword(s):  
Lactococcus Lactis ◽  
Cell Walls ◽  
Cell Envelope ◽  
Laboratory Strain ◽  
Proteolytic Cleavage ◽  
Zymogram Analysis ◽  
Sds Page ◽  
Derivatives Of ◽  
Free Strains

The autolysin, N-acetyl muramidase (AcmA), of six commercial Lactococcus lactis subsp. cremoris starter strains and eight Lc. lactis subsp. cremoris derivatives or plasmid-free strains was shown by renaturing SDS-PAGE (zymogram analysis) to be degraded by the cell envelope proteinase (lactocepin; EC 3.4.21.96) after growth of strains in milk at 30 °C for 72 h. Degradation of AcmA was less in starter strains and derivatives producing lactocepin I/III (intermediate specificity) than in strains producing lactocepin I. This supports previous observations on AcmA degradation in derivatives of the laboratory strain Lc. lactis subsp. cremoris MG1363 (Buist et al. Journal of Bacteriology180 5947–5953 1998). In contrast to the MG1363 derivatives, however, the extent of autolysis in milk of the commercial Lc. lactis subsp. cremoris starter strains in this study did not always correlate with lactocepin specificity and AcmA degradation. The distribution of autolysins within the cell envelope of Lc. lactis subsp. cremoris starter strains and derivatives harvested during growth in milk was compared by zymogram analysis. AcmA was found associated with cell membranes as well as cell walls and some cleavage of AcmA occurred independently of lactocepin activity. An AcmA product intermediate in size between precursor (46 kDa) and mature (41 kDa) forms of AcmA was clearly visible on zymograms, even in the absence of lactocepin I activity. These results show that autolysis of commercial Lc. lactis subsp. cremoris starter strains is not primarily determined by AcmA activity in relation to lactocepin specificity and that proteolytic cleavage of AcmA in vivo is not fully defined.

scholarly journals In vivo application of recombinant interleukin 2 in the immunotherapy of established cytomegalovirus infection.

1987 ◽  
Vol 165 (3) ◽  
pp. 650-656 ◽  
Author(s):  
M J Reddehase ◽  
W Mutter ◽  
U H Koszinowski
Keyword(s):  
Interleukin 2 ◽  
Immunocompromised Host ◽  
Antiviral Effect ◽  
Cmv Infection ◽  
Recombinant Interleukin 2 ◽  
Population Doublings ◽  
Cmv Disease ◽  
Host Tissues ◽  
Effector Population

We have shown in a murine model system for cytomegalovirus (CMV) disease in the immunocompromised host that in vivo application of recombinant human IL-2 (rhIL-2) can enhance the antiviral effect of a limited number of CD8+T lymphocytes, not only in prophylaxis, but also in therapy, when virus has already colonized host tissues. The observed net effect of IL-2 was consistent with the assumption of daily effector population doublings. The prospects for IL-2-supported immunotherapy of established CMV infection depend upon the tissues involved in disease. It appears that the prospects for controlling established CMV adrenalitis are less promising than for a therapy of interstitial CMV pneumonia.

Structures of major pilins in Clostridium perfringens demonstrate dynamic conformational change

2019 ◽  
Vol 75 (8) ◽  
pp. 718-732 ◽  
Author(s):  
Eiji Tamai ◽  
Seiichi Katayama ◽  
Hiroshi Sekiya ◽  
Hirofumi Nariya ◽  
Shigehiro Kamitori
Keyword(s):  
Conformational Change ◽  
Clostridium Perfringens ◽  
Bacterial Cell ◽  
Double Helix ◽  
Gram Positive Bacteria ◽  
Left Handed ◽  
Initial Adhesion ◽  
Practical Model ◽  
Host Tissues

Pili in Gram-positive bacteria are flexible rod proteins associated with the bacterial cell surface, and they play important roles in the initial adhesion to host tissues and colonization. The pilus shaft is formed by the covalent polymerization of major pilins, catalyzed by sortases, a family of cysteine transpeptidases. Here, X-ray structures of the major pilins from Clostridium perfringens strains 13 and SM101 and of sortase from strain SM101 are presented with biochemical analysis to detect the formation of pili in vivo. The major pilin from strain 13 adopts an elongated structure to form noncovalently linked polymeric chains in the crystal, yielding a practical model of the pilus fiber structure. The major pilin from strain SM101 adopts a novel bent structure and associates to form a left-handed twist like an antiparallel double helix in the crystal, which is likely to promote bacterial cell–cell interactions. A modeling study showed that pilin with a bent structure interacts favorably with sortase. The major pilin from strain SM101 was considered to be in an equilibrium state between an elongated and a bent structure through dynamic conformational change, which may be involved in pili-mediated colonization and sortase-mediated polymerization of pili.

O-Acetylated peptidoglycan: its occurrence, pathobiological significance, and biosynthesis

1992 ◽  
Vol 38 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Anthony J. Clarke ◽  
Claude Dupont
Keyword(s):  
Cell Walls ◽  
Biological Effects ◽  
Clinical Importance ◽  
Hydroxyl Group ◽  
Human Pathogens ◽  
Structural Units ◽  
Composition And Structure ◽  
And Staphylococcus Aureus

Bacterial cell walls and their structural units, particularly peptidoglycan, induce a vast variety of biological effects in host organisms. The pathobiological effects of peptidoglycan are greatly enhanced by various modifications and substitutions to its basic composition and structure. One such modification is the presence of acetyl moieties at theC-6 hydroxyl group of N-acetylmuramyl residues, and to date, 11 species of eubacteria, including some important human pathogens, such as Neisseria gonorrhoeae, Proteus mirabilis, and Staphylococcus aureus, are known to possess O-acetylated peptidoglycan. This review addresses the influence of O-acetylation of peptidoglycan on its resistance to degradation both in vitro and in vivo, the clinical importance of the modification, and the currently held views on the pathway for its biosynthesis. Key words: peptidoglycan, murein, O-acetylation, lysozyme, arthritis.

scholarly journals In vivo fluorescence correlation microscopy (FCM) reveals accumulation and immobilization of Nod factors in root hair cell walls

2000 ◽  
Vol 21 (1) ◽  
pp. 109-119 ◽  
Author(s):  
Joachim Goedhart ◽  
Mark A. Hink ◽  
Antonie J. W. G. Visser ◽  
Ton Bisseling ◽  
Theodorus W. J. Gadella
Keyword(s):  
Hair Cell ◽  
Root Hair ◽  
Cell Walls ◽  
Nod Factors ◽  
Fluorescence Correlation ◽  
In Vivo Fluorescence ◽  
Root Hair Cell ◽  
Correlation Microscopy ◽  
Fluorescence Correlation Microscopy
Sign in / Sign up

Export Citation Format

Share Document