TAE684 (NVP-TAE684) Mechanism
ALK consists of an extracellular domain, a hydrophobic transmembrane domain, and an intracellular kinase domain. [1] Specifically, the extracellular domain comprises two MAM domains separated by an LDL-A domain, and a glycine-rich domain that precedes the transmembrane (TM)-spanning domain. For the catalytic domain, a smaller N- lobe is connected to a larger C- lobe by the hinge region, and the ATP-binding site is located at the interlobe cleft. [2] The ALK kinase domain also contains three tyrosines in the activation loop (YxxxYY). [3]
The crystal structure reveals that NVP-TAE684 binds in the ATP-binding site. The hinge interactions include hydrogen bonds between the pyrimidine and amino nitrogens of TAE684 and the backbone nitrogen and oxygen of Met1199, respectively. The pyrimidine ring is situated below Ala1148 and above Leu1256, with the chlorine substituent directed toward the back of the pocket. The phenyl ring in the terminal fills the cavity underneath the glycine-rich loop and makes hydrophobic interactions with Val1130 and the Gly1123-His1124 segment. The sulfonyl oxygens of the isopropylsulfonyl substituent are directed toward Lys1150, and the isopropyl group is directed downward and packs against Asp1270 at the back of the pocket. Another phenyl ring of TAE684 is sandwiched between Leu1122 and Gly1202, and the attached methoxy group is in a cavity formed by the side chain of Glu1132 and the Leu1198-Met1199-Ala1200 hinge segment. The piperidinyl-1-methylpiperazine group packs against the outer side of the αD helix by Van der Waals interactions with Asp1203, Ser1206, and Glu1210. [3]
References
[1] Iwahara T, et al. Oncogene. 1997, 14(4), 439-449.
[2] Lee CC, et al. Biochem J. 2010, 430(3), 425-437.
[3] Bossi RT, et al. Biochemistry. 2010, 49(32), 6813-6825.