Inhibition of Grb2 SH2 domain binding by non-phosphate-containing ligands. 2. 4-(2-Malonyl)phenylalanine as a potent phosphotyrosyl mimetic.
Nonhydrolyzable phosphotyrosyl (pTyr) mimetics serve as important components of many competitive Grb2 SH2 domain inhibitors. To date, the most potent of these inhibitors have relied on phosphonate-based structures to replace the 4-phosphoryl group of the parent pTyr residue. Reported herein is the design and evaluation of a new pTyr mimetic, p-malonylphenylalanine (Pmf), which does not contain phosphorus yet, in Grb2 SH2 domain binding systems, approaches the potency of phosphonate-based pTyr mimetics. When incorporated into high affinity Grb2 SH2 domain-directed platforms, Pmf is 15-20 times more potent than the closely related previously reported pTyr mimetic, O-malonyltyrosine (OMT). Pmf-containing inhibitors show inhibition constants as low as 8 nM in extracellular Grb2 binding assays and in whole cell systems, effective blockade of both endogenous Grb2 binding to cognate erbB-2, and downstream MAP kinase activation. Evidence is provided that use of an N(alpha)()-oxalyl auxiliary enhances effectiveness of Pmf and other inhibitors in both extracellular and intracellular contexts. As one of the most potent Grb2 SH2 domain-directed pTyr mimetics yet disclosed, Pmf may potentially have utility in the design of new chemotherapeutics for the treatment of various proliferative diseases, including breast cancer.
Gao
Y
Y
Laboratory of Medicinal Chemistry, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Luo
J
J
Yao
Z J
ZJ
Guo
R
R
Zou
H
H
Kelley
J
J
Voigt
J H
JH
Yang
D
D
Burke
T R
TR
D048868:Adaptor Proteins, Signal Transducing; D002460:Cell Line; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D051380:GRB2 Adaptor Protein; D006801:Humans; D008024:Ligands; D008314:Malonates / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D008958:Models, Molecular; D018716:Molecular Mimicry; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D019000:Phosphotyrosine / Q000737:chemistry*; D011485:Protein Binding; D011506:Proteins / Q000037:antagonists & inhibitors*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D013329:Structure-Activity Relationship; D018909:src Homology Domains
D048868:Adaptor Proteins, Signal Transducing; D004791:Enzyme Inhibitors; D051380:GRB2 Adaptor Protein; D008024:Ligands; D008314:Malonates; D020928:Mitogen-Activated Protein Kinases; D010649:Phenylalanine; D019000:Phosphotyrosine; D011506:Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; C406229:4-(2-malonyl)phenylalanine; C495948:GRB2 protein, human