PHD Student no. 9​/2025​/ICHB​/PSD

Institute of Bioorganic Chemistry Polish Academy of Sciences

Organisation/Company Institute of Bioorganic Chemistry Polish Academy of Sciences Department Poznań Doctoral School of the Institutes of the Polish Academy of Sciences Research Field Biological sciences » Biology Chemistry Researcher Profile First Stage Researcher (R1) Positions PhD Positions Final date to receive applications 31 Aug 2026 - 23:59 (Europe/Brussels) Country Poland Type of Contract Temporary Job Status Full-time Hours Per Week 40 Is the job funded through the EU Research Framework Programme?

Not funded by a EU programme Reference Number 9/2026/ICHB/PSD Is the Job related to staff position within a Research Infrastructure? No

G-quadruplex, DNA aptamer, hairpin, thrombin

Research topic:
Modified nucleotide residues as potential tool to increase aptamer - target protein interaction

Aptamers are short, single strands of DNA or RNA that act like custom-made molecular keys. Their specific sequence tells them exactly how to fold into complex 3D shapes – some look like hairpins (such as Toggle-25t), while others form G-quadruplexes (like RE31 or RV66). It is this unique shape that allows them to bind to a target protein and switch its activity on or off.

While aptamers are incredibly versatile, they face a natural limitation. They are built from only four basic building blocks (nucleotides), whereas the proteins they target are made of 20 different amino acids. This lack of chemical variety means that aptamers sometimes struggle to bind their targets tightly enough. To overcome this, scientists have begun altering these building blocks. A major leap forward involved adding modifications that mimic amino acids (like SOMA-DNA), which significantly boosted how strongly aptamers could bind to proteins through hydrophobic interactions.

Inspired by these advancements, we have developed novel chemical compounds called SUNAs (Slow Off-Rate Unlocked Nucleic Acids). These modifications make the aptamer backbone more flexible, allowing it to bind to protein more effectively and stay attached for much longer. We are also exploring other ways to strengthen these connections, such as: replacement of oxygen with sulfur in the aptamer bonds or using modified sugar moieties (like 2’-fluoroarabinose) to stabilize the structure.

In this project, we propose to expand knowledge regarding the usefulness of these modifications for developing variants of RE31, RV66, and Toggle-25t aptamers with enhanced affinity for target proteins. A detailed understanding of these processes and mechanisms at the molecular level could enable the design of new versions of known inhibitors, which, in turn, could contribute to the improvement of therapeutic methods.

• Research and doctoral theses shall be carried out within the project 2024/55/D/NZ7/02686, entitled “Modified nucleotide residues as potential tool to increase aptamer - target protein interaction”, funded by the National Science Center
• PhD students shall receive a stipend in the gross amount of ca4300 PLN for the period of 24 months with the possibility of extending up to 48 months, and with the possibility of increasing the amount of the stipend after the mid-term evaluation (in accordance with the current regulation of the Minister –5500.50 PLN gross).
• PhD students shall be subject to social insurance, pursuant to article. 6 section 1 passage 7b of the act of October 13th, 1998 on the social insurance system (Journal of Laws of 2019, item 300, 303 and 730).
• Access to a Multisport card, group insurance, and social benefits (including subsidized vacation leave and reimbursement for cultural event tickets).

PhD students shall receive a stipend in the gross amount of ca4300 PLN for the period of 24 months

• MSc degree in biology, chemistry, or a related field, or fulfilling the conditions stipulated in article 186, section 2 of the Act of July 20th, 2018, Law on Higher Education and Science (Journal of Laws of 2018, item 1668, as amended).
• Experience in laboratory work in the field of biology and biochemistry
• Experience in the field of…