an enzyme-linked immunosorbent assay for neopterin using penicillinase as marker enzyme is reported here by polyclonal antibodies against neopterin conjugated to bovine serum albumin which were raised in rabbits. immunoglobulin fractions were purified and coated on wells of microtiter plates. a chain heterology was introduced in neopterin derivative and conjugated to penicillinase. the assay is...

ATP hydrolysis (by RecA protein) fundamentally alters the properties of RecA protein-mediated DNA strand exchange reactions. ATP hydrolysis renders DNA strand exchange unidirectional, greatly increases the lengths of hybrid DNA created, permits the bypass of heterologous DNA insertions in one or both DNA substrates, and is absolutely required for exchange reactions involving four DNA strands. T...

Homologous recombination plays a key role in generating genetic diversity, while maintaining protein functionality. The mechanisms by which RecA enables a single-stranded segment of DNA to recognize a homologous tract within a whole genome are poorly understood. The scale by which homology recognition takes place is of a few tens of base pairs, after which the quest for homology is over. To stu...

The purpose of the article is to show how E. Levinas reveals preontological possibilities an ethical relationship, which built not on principle a totalizing logos and order, overwhelming suppressed, but “relationship without relationship”, has pronounced methodological consequences. first part reconstructs Levinas’ criticism classical ontological tradition, inevitably reductive in relation obje...

The species barrier in prion infectivity is believed to reside in the degree of amino acid sequence heterology between the infectious prion protein, PrP(Sc), of the donor and the normal PrP of the host. bring new evidence that distinct PrP(Sc) species or prion strains may have different conformations even when they have identical amino acid sequence and that the conformation of the exogenous pr...

Homologous recombination plays a key role in generating genetic diversity, while maintaining protein functionality. The mechanisms by which RecA enables a single-stranded segment of DNA to recognize a homologous tract within a whole genome are poorly understood. The scale by which homology recognition takes place is of a few tens of base pairs, after which the quest for homology is over. To stu...