Structure
and Function of Ecto-ATPases and Ecto-Apyrases
The long-term goal of my laboratory is the determination
of the structures and functions of the cell membrane and soluble
ecto-nucleotidases. These enzymes are collectively called ecto-Nucleoside
Triphosphate Diphosphohydrolases (eNTPDases).
The physiological importance of the eNTPDases
is just beginning to be appreciated. Receptors for extracellular
nucleotides (purinergic and pyrimidinergic receptors) occur in
many parts of the body, perform many different physiological functions,
and respond to different types of nucleotides (e.g., ATP vs. UTP),
as well as to different phosphorylation states of each nucleotide
(e.g., ATP vs. ADP vs. AMP vs. adenosine). The ecto-nucleotidases
are important for the regulation of many physiological and pathological
signaling processes under purinergic control, including pain perception
and maintenance of hemostasis via hydrolysis of the platelet activator,
ADP. They have also been implicated as important for cell adhesion,
angiogenesis, and cancer development.
Our laboratory utilizes immunological, molecular
biological, biophysical, structural biological, and basic biochemical
techniques to study the structures and functions of these enzymes.
We are currently using site-directed mutagenesis and protein chemistry
techniques to define the regions of the proteins important for
formation and stabilization of the native oligomeric structure
needed for function of the membrane-bound nucleotidases. We are
also utilizing bacterial expression systems to generate sufficient
quantities of the soluble human nucleotidases for protein chemistry
experiments and X-ray crystallography, to define and modify the
active sites in order to understand and manipulate the functions
of these enzymes in various biological systems.
Publications
