Campylobacter jejuni is an important cause of human foodborne gastroenteritis; strategies to prevent infection are hampered by a poor understanding of the complex interactions between host and pathogen. Previous work showed that C. jejuni could bind human histo-blood group antigens (BgAgs) in vitro and that BgAgs could inhibit the binding of C. jejuni to human intestinal mucosa ex vivo. Here, the major flagella subunit protein (FlaA) and the major outer membrane protein (MOMP) were identified as BgAg-binding adhesins in C. jejuni NCTC11168. Significantly, the MOMP was shown to be O-glycosylated at Thr268; previously only flagellin proteins were known to be O-glycosylated in C. jejuni. Substitution of MOMP Thr268 led to significantly reduced binding to BgAgs. The O-glycan moiety was characterized as Gal(β1–3)-GalNAc(β1–4)-GalNAc(β1–4)-GalNAcα1-Thr268; modelling suggested that O-glycosylation has a notable effect on the conformation of MOMP and this modulates BgAg-binding capacity. Glycosylation of MOMP at Thr268 promoted cell-to-cell binding, biofilm formation and adhesion to Caco-2 cells, and was required for the optimal colonization of chickens by C. jejuni, confirming the significance of this O-glycosylation in pathogenesis.

Specific acid-catalyzed solvolysis of 1-methoxy-1,4-dihydronaphthalene (1-OMe) or 2-methoxy-1,2-dihydronaphthalene (2-OMe) in 25 vol % acetonitrile in water yields mainly the elimination product naphthalene, which is accompanied by a trace of 2-hydroxy-1,2-dihydronaphthalene (2-OH). No intramolecular rearrangement or formation of the alcohol 1-OH from 1-OMe was found. The nucleophilic selectivity between added azide ion and solvent water was measured as k N3 /k HOH ) 2.1 × 10 4 (ratio of second-order rate constants). The results indicate a relatively stable benzallylic carbocation toward trapping by nucleophiles (k w ) 1 × 10 7 s -1 ). However, the elimination-to-substitution ratio with solvent water as base/nucleophile is large. Thus, in contrast to other carbocations of similar reactivity toward nucleophiles, the barrier to dehydronation is very low, k e ) 1.6 × 10 10 s -1 , and accordingly, this step does not show any catalysis from added general bases. The heats of reaction of the solvolytic eliminations of 1-OH and 2-OH are ∆H ) -23.7 and -18.4 kcal mol -1 , respectively, as measured by microcalorimetry.

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The non-integrin laminin receptor (LAMR1/RPSA) and galectin-3 (Gal-3) are multi-functional host molecules with roles in diverse pathological processes, particularly of infectious or oncogenic origins. Using bimolecular fluorescence complementation and confocal imaging, we demonstrate that the two proteins homo- and heterodimerize, and that each isotype forms a distinct cell surface population. We present evidence that the 37 kDa form of LAMR1 (37LRP) is the precursor of the previously described 67 kDa laminin receptor (67LR), whereas the heterodimer represents an entity that is distinct from this molecule. Site-directed mutagenesis confirmed that the single cysteine (C173) of Gal-3 or lysine (K166) of LAMR1 are critical for heterodimerization. Recombinant Gal-3, expressed in normally Gal-3-deficient N2a cells, dimerized with endogenous LAMR1 and led to a significantly increased number of internalized bacteria (Neisseria meningitidis), confirming the role of Gal-3 in bacterial invasion. Contact-dependent cross-linking determined that, in common with LAMR1, Gal-3 binds the meningococcal secretin PilQ, in addition to the major pilin PilE. This study adds significant new mechanistic insights into the bacterial–host cell interaction by clarifying the nature, role and bacterial ligands of LAMR1 and Gal-3 isotypes during colonization.

This work reports on the synthesis of three new l -lysine-based organogelators bis(N 2 -alkanoyl-N 6 - l -lysyl ethylester)oxalylamides, where alkanoyls are lauroyl, myristoyl, and palmitoyl. The gels of these gelators were prepared with high yields in eco-friendly solvents commonly used in cosmetics such as ethyl and isopropyl esters of lauric and myristic acids, liquid paraffin, 1-decanol, and 1,2-propanediol. Fourier transform infrared measurements revealed the involvement of intermolecular hydrogen bonds in the gelation. Scanning electron microscopy images of xerogels indicated different morphologic patterns with regard to the alkanoyl chain length and the solvent employed in their preparation. The gel formation was supported by rheological measurements. Three gels prepared in liquid paraffin were loaded with naproxen (Npx) with a quite high loading capacity (up to 166.6% as percentage of gelator) without gel disruption. The release of Npx from the gel matrix into the buffered solution at physiologic pH was evaluated using UV–vis spectroscopy. The results revealed that the release rate of Npx from the organogels significantly retarded with increasing organogelator concentration, whereas it enhanced with increasing Npx concentration. The rate was also found to be pH-dependent; the lower the pH, the lower the rate. Furthermore, molecular dynamic calculations performed on the octamer of myristoyl-bearing gelator ( N 2 M/N 6 Lys ) in 1,2-propanediol provided useful information regarding the structural properties of the gels, which may be of interest to interpret the structure of the gel matrix. Altogether, this work provided valuable outcomes, which may be relevant to the pharmaceutical industry. It may be suggested that l -lysine-based gels have potentials in the delivery of nonsteroidal anti-inflammatory drug molecules. Besides, the release of the drug can be fine-tuned by the correct choice of gelator–solvent combination.