Methods and reagents for analyzing protein-protein interfaces
The present disclosure provides methods and reagents useful for analyzing protein-protein interfaces such as interfaces between a presenter protein (e.g., a member of the FKBP family, a member of the cyclophilin family, or PIN1) and a target protein. In some embodiments, the target and/or presenter proteins are intracellular proteins. In some embodiments, the target and/or presenter proteins are mammalian proteins.
1. A compound, or salt thereof, which binds to cyclophilin and which has the structure:
A-L-B,
wherein A is a cyclophilin binding moiety having the structure of Formula III:
wherein Z 3 and Z 4 are each, independently, hydroxyl, optionally substituted C 1 -C 6 alkyl, optionally substituted C 1 -C 6 heteroalkyl, or Z 3 and Z 4 combine to form, with the atoms to which they are attached, an optionally substituted 13 to 40 member macrocycle;
Z 4 comprises a point of attachment to L;
R 5 is optionally substituted C 1 -C 6 alkyl, optionally substituted C 2 -C 6 alkenyl, optionally substituted C 2 -C 6 alkynyl, optionally substituted C 1 -C 6 heteroalkyl, optionally substituted C 2 -C 6 heteroalkenyl, optionally substituted C 2 -C 6 heteroalkynyl, optionally substituted C 3 -C 10 carbocyclyl, optionally substituted C 6 -C 10 optionally substituted C 6 -C 10 aryl C 1 -C 6 alkyl, optionally substituted C 2 -C 9 heterocyclyl, or optionally substituted C 2 -C 9 heterocyclyl C 1 -C 6 alkyl;
R 6 is optionally substituted C 1 -C 6 alkyl;
L is a linker having the structure:
A 1 -(B 1 ) f —(C 1 ) g —(B 2 ) h -(D)-(B 3 ) i —(C 2 ) j —(B 4 ) k -A 2
wherein A 1 is a bond between the linker and A; A 2 is a bond between B and the linker; B 1 , B 2 , B 3 , and B 4 each, independently, is selected from optionally substituted C 1 -C 2 alkyl, optionally substituted C 1 -C 3 heteroalkyl, O, S, and NR N ; R N is hydrogen, optionally substituted C 1-4 alkyl, optionally substituted C 2-4 alkenyl, optionally substituted C 2-4 alkynyl, optionally substituted C 2-6 heterocyclyl, optionally substituted C 6-12 aryl, or optionally substituted C 1-7 heteroalkyl; C 1 and C 2 are each, independently, selected from carbonyl, thiocarbonyl, sulphonyl, or phosphoryl; f, g, h, l, j, and k are each, independently, 0 or 1; and D is optionally substituted C 1-10 alkyl, optionally substituted C 2-10 alkenyl, optionally substituted C 2-10 alkynyl, optionally substituted C 2-6 heterocyclyl, optionally substituted C 6-12 aryl, optionally substituted C 2 -C 10 polyethylene glycol, or optionally substituted C 1-10 heteroalkyl, or a chemical bond linking A 1 -(B 1 ) f —(C 1 ) g —(B 2 ) h — to —(B 3 ) i —(C 2 ) j —(B 4 ) k -A 2 ; and
B is a cross-linking group, wherein the cross-linking group is a maleimide, vinyl sulfone having the structure
isocyanate, isothiocyanate, or haloheteroaryl.
2. The compound, or salt thereof, of claim 1 , wherein the cross-linking group is a maleimide.
3. The compound, or salt thereof, of claim 1 , wherein the interaction between the cyclophilin binding moiety and cyclophilin is non-covalent.
4. The compound, or salt thereof, of claim 1 , wherein the cyclophilin binding moiety is a cyclophilin binding moiety capable of binding PP1A, CYPB, CYPC, CYP40, CYPE, CYPD, NKTR, SRCyp, CYPH, CWC27, CYPL1, CYP60, CYPJ, PPIL4, PPIL6, RANBP2, or PPWD1.