Biotin-labeled oligonucleotides with extraordinarily long tethering arms.

We describe synthesis of four novel biotin phosphoramidites with tethering arms ranging from 20 to 74 atoms in length. One of these phosphoramidites is a uridine derivative with a biotin moiety attached through the 2'-position. The biotin phosphoramidites were synthetized based on robust and efficient methoxyoxalamido (MOX) and succinimido (SUC) precursor strategies from MOX/SUC precursors containing a secondary hydroxyl.

Methoxyoxalamido chemistry in the synthesis of novel amino linker and spacer phosphoramidites: a robust means for stability, structural versatility, and optimal tether length.

We have developed a general route to the synthesis of novel amino linker and spacer phosphoramidites utilizing methoxyoxalamido (MOX) chemistry. The synthesis makes use of readily available and inexpensive primary aliphatic amino alcohols and diamines to produce a rich and diverse variety of phosphoramidites. Among these are monomers with exceptionally long (up to 56 atoms in length) amphipathic tethering arms.

Novel biotin phosphoramidites with super-long tethering arms.

A number of novel biotin phosphoramidites, possessing exceptionally long and uncharged tethering arms, were synthesized from methoxyoxalamido (MOX) and succinimido (SUC) precursors. Included among these monomers is a uridine derivative with the biotin moiety attached through the 2'-position. Some of these phosphoramidites were used to make 5'-biotinylated primers, which were applied in direct sequencing of genomic DNA and capture of Sanger fragment pools.

Stability, vigor, and inherent versatility of novel amino linker and spacer phosphoramidites.

Novel amino linker and spacer phosphoramidites were synthesized from methoxyoxalamido (MOX) percursors possessing a secondary hydroxyl, which when phosphitylated endowed stability to the corresponding phosphoramidites. The synthetic strategy is robust, and the chemistry is reactive towards a variety of primary aliphatic diamines and amino alcohols to produce distinctly unique phosphoramidites. The selection of building blocks determines the length and physico-chemical properties of the phosphoramidite tethering arms, and the synthesis can be specifically tailored to suit individual requirement.

The extracellular domain of CD4 receptor possesses a protein kinase activity.

The CD4 receptor of T-helper cells is an essential participant in immune response formation and HIV infection. We report here that the extracellular domains of CD4 receptor can catalyze the phosphotransferase (kinase) reaction. Incubation of rsCD4 in solution with [gamma-32P]ATP results in the Ca2+-dependent autophosphorylation of the protein presumably at a His residue because the reaction is prevented by the diethylpyrocarbonate treatment.