Chemical Linkage to Injected Tissues Is a Distinctive Property of Oxidized Avidin

We recently reported that the oxidized avidin, named AvidinOX®, resides for weeks within injected tissues as a consequence of the formation of Schiff's bases between its aldehyde groups and tissue protein amino groups. We also showed, in a mouse pre-clinical model, the usefulness of AvidinOX for the delivery of radiolabeled biotin to inoperable tumors. Taking into account that AvidinOX is the first oxidized glycoprotein known to chemically link to injected tissues, we tested in the mouse a panel of additional oxidized glycoproteins, with the aim of investigating the phenomenon. We produced oxidized ovalbumin and mannosylated streptavidin which share with avidin glycosylation pattern and tetrameric structure, respectively and found that neither of them linked significantly to cells in vitro nor to injected tissues in vivo, despite the presence of functional aldehyde groups. The study, extended to additional oxidized glycoproteins, showed that the in vivo chemical conjugation is a distinctive property of the oxidized avidin. Relevance of the high cationic charge of avidin into the stable linkage of AvidinOX to tissues is demonstrated as the oxidized acetylated avidin lost the property. Plasmon resonance on matrix proteins and cellular impedance analyses showed in vitro that avidin exhibits a peculiar interaction with proteins and cells that allows the formation of highly stable Schiff's bases, after oxidation

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Not AvailableCrop productivity is greatly affected by soil salinity; therefore, improvement in salinity tolerance of crops is a major goal in salt-tolerant breeding. The Salt Overly Sensitive (SOS) signal-transduction pathway plays a key role in ion homeostasis and salt tolerance in plants. In plants pumping of Na+ from the root cells is mediated by the plasma membrane Na+/H+ antiporter (SOS1) which plays important role in preventing the accumulation of toxic levels of Na+ in cytosol. In the present study, OsSOS1 (NHX7), gene was overexpressed in rice (var-Vikas) by Agrobacterium mediated In Planta transformation technique. To screen putative T1 plants for salt tolerance, stringent salt screening test was followed and root and shoot growth of transformants were used as selection criterion. Some of the putative transgenics showed significantly higher root growth compared to wild type. To confirm the presence of transgene in putative T1 transgenic plants, PCR based approach was followed using genomic DNA. The result showed that 16 % of the selected seedlings from the stringent salt screening test were PCR positives. Five selected lines were positive for RT-PCR analysis. Physiological studies such as chlorophyll content, membrane permeability, cell viability and sodium /potassium content analysis were also conducted to assess their levels of tolerance. Some of the T1 transformants showed lower percent reduction in chlorophyll content and less membrane leakage, higher cell viability and maintained higher K/Na ratio after NaCl treatment compared to wild type. These results clearly demonstrate that transgenic rice plants overexpressing OsSOS1 have better salt-tolerance. This could be attributed to extrusion of excess Na+ from cytosol into the apoplast and thereby reducing the toxic effects of Na+in the cell.ICA