Graduation Year


Document Type




Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department


Major Professor

Ioannis Gelis, Ph.D.

Committee Member

David Merkler, Ph.D.

Committee Member

Randy Larsen, Ph.D.

Committee Member

Gloria Ferreira, Ph.D.


Arylalkylamine N-acetyltransferase, Cdc37, Hsp90, TIMP2


Characterization of protein structural properties is crucial to determine its role in normal and pathological conditions. In this dissertation, we have employed NMR spectroscopy in a combination of other biochemical and biophysical techniques to investigate the catalytic function, the molecular mechanism, and nature of the interactions of bmAANAT3, Cdc37, and TIMP2, respectively.

In the first project, we have employed an arylalkylamine N-acetyltransferases (AANATs) from Bombyx mori (bmAANAT3) to determine the role of the acetyl-group in coordinating the catalytic cycle in this family of enzymes. We have found that the occupancy of the acetyl-moiety in the catalytic funnel of these enzymes coordinates the ordered progress of their catalytic cycle by regulating the conformational properties of their acetyl-group donor and acceptor binding sites.

In the second project, the catalytic domain of the Hsp90 client kinase bRaf has been used to investigate the role of kinome specific Hsp90 cochaperone Cdc37 in the Hsp90 chaperone machinery. Our data has revealed that Cdc37 sorts a broad range of kinases into Hsp90 clients and nonclients by scanning their thermal stability through locally unfolding only the client kinases.

Finally, we have used the N-terminal domain of the tissue inhibitor metalloproteinase-2 (N-TIMP2) to provide an insight into the extracellular interaction activity of Hsp90. Our data has shown that both Hsp90 and its middle domains (mHsp90)

interact with N-TIMP2 in a transient low-affinity regime. However, in both states of the Hsp90, this interaction is driven by a subset of hydrophobic residues located at the surface of N-TIMP2.