| 1. |
- Hood, D W, et al.
(författare)
-
Genetic basis for expression of the major globotetraose-containing lipopolysaccharide from H-influenzae strain Rd (RM118)
- 2001
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 11:11, s. 957-967
-
Tidskriftsartikel (refereegranskat)abstract
- A genetic basis for the biosynthetic assembly of the globotetraose containing lipopolysaccharide (LPS) of Haemophilus influenzae strain RM118 (Rd) was determined by structural analysis of LPS derived from mutant strains. We have previously shown that the parent strain RM118 elaborates a population of LPS molecules made up of a series of related glycoforms differing in the degree of oligosaccharide chain extension from the distal heptose residue of a conserved phosphorylated inner-core element, L-alpha -D-Hepp-(1-->2)-L-alpha -D-Hepp-(1-->3)-[beta -D-Glcp-(1-->4)-]-L-alpha -D-Hepp-(1-->5)-alpha -Kdo. The fully extended LPS glycoform expresses the globotetraose structure, beta -D-GalpNAc-(1-->3)-alpha -D-Galp(1-->4)-beta -D-Galp-(1-->4)-beta -D-Glcp. A fingerprinting strategy was employed to establish the structure of LPS from strains mutated in putative glycosyltransferase genes compared to the parent strain. This involved glycose and linkage analysis on intact LPS samples and analysis of O-deacylated LPS samples by electrospray ionization mass spectrometry and 1D H-1-nuclear magnetic resonance spectroscopy. Four genes, lpsA, lic2A, lgtC, and lgtD, were required for sequential addition of the glycoses to the terminal inner-core heptose to give the globotetraose structure. lgtC and lgtD were shown to encode glycosyltransferases by enzymatic assays with synthetic acceptor molecules. This is the first genetic blueprint determined for H. influenzae LPS oligosaccharide biosynthesis, identifying genes Involved in the addition of each glycose residue.
|
|
| 2. |
- Hood, D W, et al.
(författare)
-
Biosynthesis of cryptic lipopolysaccharide glycoforms in Haemophilus influenzae involves a mechanism similar to that required for O-antigen synthesis
- 2004
-
Ingår i: Journal of Bacteriology. - 0021-9193 .- 1098-5530. ; 186:21, s. 7429-7439
-
Tidskriftsartikel (refereegranskat)abstract
- It is generally thought that mucosal bacterial pathogens of the genera Haemophilus, Neisseria, and Moraxella elaborate lipopolysaccharide (LPS) that is fundamentally different from that of enteric organisms that express O-specific polysaccharide side chains. Haemophilus influenzae elaborates short-chain LPS that has a role in the pathogenesis of H. influenzae infections. We show that the synthesis of LPS in this organism can no longer be as clearly distinguished from that in other gram-negative bacteria that express an O antigen. We provide evidence that a region of the H. influenzae genome, the hmg locus, is involved in the synthesis of glycoforms in which tetrasaccharide units are added en bloc, not stepwise, to the normal core glycoforms, similar to the biosynthesis of an O-antigen.
|
|
| 3. |
- Li, J J, et al.
(författare)
-
Electrophoretic and mass spectrometric strategies for profiling bacterial lipopolysaccharides
- 2005
-
Ingår i: MOLECULAR BIOSYSTEMS. - : Royal Society of Chemistry (RSC). - 1742-206X .- 1742-2051. ; 1:1, s. 46-52
-
Tidskriftsartikel (refereegranskat)abstract
- Capillary electrophoresis (CE) is a high-resolution separation technique that has been widely used for trace analysis in biological samples. On-line capillary electrophoresis-electro spray mass spectrometry (CE-MS) was developed for the analysis of lipopolysaccharide (LPS) glycoforms from the gram-negative bacteria, Haemophilus influenzae. In this paper, we report on the application of CE-MS to characterize structural differences in O-deacylated LPS samples from H. influenzae strains Rd 11.7 and 375.1. The resolution capability of on-line CE-MS was first demonstrated by analysis of a complex LPS mixture from H. influenzae strain Rd 11.7. This strain contains a mixture of isomeric glycoforms differing in the number and positions of hexose moieties. Sialic acid containing glycoforms were also determined. Structural features of LPS from a lic1 mutant of H. influenzae strain 375 (375.1) were studied using on-line CE-MS/MS. With the separation provided by CE, two isomeric glycoforms differing in the location of phosphoethanolamine substituents were characterized by tandem mass spectrometry.
|
|
| 4. |
|
|
| 5. |
- Van der Heyden, J H A, et al.
(författare)
-
Socioeconomic inequalities in lung cancer mortality in 16 European populations.
- 2009
-
Ingår i: Lung Cancer. - : Elsevier BV. - 0169-5002 .- 1872-8332. ; 63:3, s. 322-330
-
Tidskriftsartikel (refereegranskat)abstract
- Important socioeconomic inequalities exist in lung cancer mortality in Europe. They are consistent with the geographical spread of the smoking epidemic. In the next decades socioeconomic inequalities in lung cancer mortality are likely to persist and even increase among women. In Southern European countries we may expect a reversal from a positive to a negative association between socioeconomic status and lung cancer mortality. Continuous efforts are necessary to tackle socioeconomic inequalities in lung cancer mortality in all European countries.
|
|
