Design and synthesis of chemical probes for the plekstrin homology domain

Phosphoinositides--Derivatives--Synthesis;Inositol;Inositol phosphates;Protein kinases;Molecular probes

Elliott, Thomas S. ; Conway, Stuart ; Conway, Stuart

University:University of St Andrews

Department:Chemistry (School of)

关键词: Phosphoinositides--Derivatives--Synthesis;    Inositol;    Inositol phosphates;    Protein kinases;    Molecular probes;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/1977/ThomasElliottPhDThesis.pdf?sequence=6&isAllowed=y

来源: DR-NTU

【 摘 要 】

The phosphatidylinositol polyphosphates play a fundamental role in intracellular signalling. Of particular importance is phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P₃], which acts by recruiting effector proteins to the cell membrane. PtdIns(3,4,5)P₃ interacts with its protein targets through selective binding domains that include the pleckstrin homology (PH) domain. The PH-domain-containing kinase, protein kinase B (PKB/Akt), which interacts with PtdIns(3,4,5)P₃, is upregulated in ~15 human malignancies. Significantly, inhibition of the PtdIns(3,4,5)P₃-PKB interaction has proved viable as a point of therapeutic intervention.There is currently a lack of small molecule probes that selectively interact with a given PH domain. Consequently, it is impossible to dissect the cellular function of PH-domain-containing proteins at a molecular level. To address this problem, we have designed and synthesised a number of derivatives of the PtdIns(3,4,5)P₃ inositol head-group – Ins(1,3,4,5)P₄. Replacement of the 5-position phosphate with a range of phosphate bioisosteres afforded compounds that displayed no binding affinity for the PH-domain of general receptor for phosphoinositides 1 (GRP1). However, it was shown that the 5-position sulfamate analogue displayed selectivity for the PH-domain of PKB.The methylphosphate biosiostere at the 1-position displayed binding for both the GRP1 PH-domain as well as the PKB PH-domain. These results demonstrate that subtle modification of the Ins(1,3,4,5)P₄ structure allows the synthesis of compounds that interact selectively with a given PH domain.We will now use these results for the synthesis of a second generation of compounds with improved PH-domain affinity and selectivity.