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Papers by hassan said
Synlett, 2012
A two-step synthesis converting thymidine into a phosphotriester building block of 5′-azido-5′-de... more A two-step synthesis converting thymidine into a phosphotriester building block of 5′-azido-5′-deoxythymidine in 60% overall yield is presented. The building block was used to assemble an oligonucleotide with an azido group at its 5′-terminus, which underwent ligation–cycloaddition, producing a strand with PCR-compatible linkage in high yield.
Nanoscale, 2013
The DNA origami method produces programmable nanoscale objects that form when one long scaffold s... more The DNA origami method produces programmable nanoscale objects that form when one long scaffold strand hybridizes to numerous oligonucleotide staple strands. One scaffold strand is dominating the field: M13mp18, a bacteriophage-derived vector 7249 nucleotides in length. The full-length M13 is typically folded by using over 200 staple oligonucleotides. Here we report the convenient preparation of a 704 nt fragment dubbed "M1.3" as a linear or cyclic scaffold and the assembly of small origami structures with just 15-24 staple strands. A typical M1.3 origami is large enough to be visualized by TEM, but small enough to show a cooperativity in its assembly and thermal denaturation that is reminiscent of oligonucleotide duplexes. Due to its medium size, M1.3 origami with globally modified staples is affordable. As a proof of principle, two origami structures with globally 5'-capped staples were prepared and were shown to give higher UV-melting points than the corresponding assembly with unmodified DNA. M1.3 has the size of a gene, not a genome, and may function as a model for gene-based nanostructures. Small origami with M1.3 as a scaffold may serve as a workbench for chemical, physical, and biological experiments.
Synlett, 2012
A two-step synthesis converting thymidine into a phosphotriester building block of 5′-azido-5′-de... more A two-step synthesis converting thymidine into a phosphotriester building block of 5′-azido-5′-deoxythymidine in 60% overall yield is presented. The building block was used to assemble an oligonucleotide with an azido group at its 5′-terminus, which underwent ligation–cycloaddition, producing a strand with PCR-compatible linkage in high yield.
Nanoscale, 2013
The DNA origami method produces programmable nanoscale objects that form when one long scaffold s... more The DNA origami method produces programmable nanoscale objects that form when one long scaffold strand hybridizes to numerous oligonucleotide staple strands. One scaffold strand is dominating the field: M13mp18, a bacteriophage-derived vector 7249 nucleotides in length. The full-length M13 is typically folded by using over 200 staple oligonucleotides. Here we report the convenient preparation of a 704 nt fragment dubbed "M1.3" as a linear or cyclic scaffold and the assembly of small origami structures with just 15-24 staple strands. A typical M1.3 origami is large enough to be visualized by TEM, but small enough to show a cooperativity in its assembly and thermal denaturation that is reminiscent of oligonucleotide duplexes. Due to its medium size, M1.3 origami with globally modified staples is affordable. As a proof of principle, two origami structures with globally 5'-capped staples were prepared and were shown to give higher UV-melting points than the corresponding assembly with unmodified DNA. M1.3 has the size of a gene, not a genome, and may function as a model for gene-based nanostructures. Small origami with M1.3 as a scaffold may serve as a workbench for chemical, physical, and biological experiments.