11 research outputs found
Evidence against a retinotopictemplate matching in honeybees’ pattern recognition. Vision Res
www.elsevier.com/locate/visre
Co-administration of CpG oligonucleotides enhances the late affinity maturation process of human anti-hepatitis B vaccine response
We assessed the avidity maturation process elicited by human immunization with alum-adsorbed HBsAg alone or with a novel adjuvant containing CpG motifs (CpG 7909). Mean avidity indexes and distribution of low- and high-avidity anti-HBs indicated that avidity maturation essentially takes place late after priming. CpG 7909 markedly enhanced this affinity maturation process, increasing the pool of high-avidity antibodies. The influence of CpG 7909 was antigen-specific, isotype-specific and distinct from the influence on anti-HBs production, as avidity did not correlate with anti-HBs IgG titers. This is the first demonstration that a novel human adjuvant may induce antibodies with higher antigen-binding affinity
Vpliv učenja in obsega žoge na spremembo hitrosti rokometnega strela
Thioredoxin, involved in numerous
redox pathways, is maintained
in the dithiol state by the nicotinamide adenine dinucleotide phosphate-dependent
flavoprotein thioredoxin reductase (TrxR). Here, TrxR from <i>Lactococcus lactis</i> is compared with the well-characterized
TrxR from <i>Escherichia coli</i>. The two enzymes belong
to the same class of low-molecular weight thioredoxin reductases and
display similar <i>k</i><sub>cat</sub> values (∼25
s<sup>–1</sup>) with their cognate thioredoxin. Remarkably,
however, the <i>L. lactis</i> enzyme is inactivated by visible
light and furthermore reduces molecular oxygen 10 times faster than <i>E. coli</i> TrxR. The rate of light inactivation under standardized
conditions (λ<sub>max</sub> = 460 nm and 4 °C) was reduced
at lowered oxygen concentrations and in the presence of iodide. Inactivation
was accompanied by a distinct spectral shift of the flavin adenine
dinucleotide (FAD) that remained firmly bound. High-resolution mass
spectrometric analysis of heat-extracted FAD from light-damaged TrxR
revealed a mass increment of 13.979 Da, relative to that of unmodified
FAD, corresponding to the addition of one oxygen atom and the loss
of two hydrogen atoms. Tandem mass spectrometry confined the increase
in mass of the isoalloxazine ring, and the extracted modified cofactor
reacted with dinitrophenyl hydrazine, indicating the presence of an
aldehyde. We hypothesize that a methyl group of FAD is oxidized to
a formyl group. The significance of this not previously reported oxidation
and the exceptionally high rate of oxygen reduction are discussed
in relation to other flavin modifications and the possible occurrence
of enzymes with similar properties