correction - Re: PI3K inhibitors

[Guest guest]

At 08:41 PM 4/13/2011, Al Janski wrote:

>For example, " protein kinases " (like PI3K),

>which catalyze the covalent addition of

>phosphate groups onto protein molecules, are

>often themselves regulated by other kinases

>adding covalent phosphate groups onto those kinases.

CORRECTION: PI3Ks are 'not' a protein

kinases. PI3Ks are " lipid kinases " that catalyze

the addition of phosphate to small regulatory fat

molecules (i.e. " phosphatidylinositols " ). PI3K =

Phosphatidyl Inositol 3-Kinase

Sorry about that..... The biochemistry is

difficult enough without such mistakes.

Kinases are a category of enzymes that catalyze

the covalent bond formation between phosphates and other

molecules in general.

BTK (Bruton Tyrosine Kinase), which is inhibited

by PCI-32765, is a " protein kinase " that

catalyzes the covalent addition of phosphate

groups onto protein molecules. Proteins are

composed of 20 different types of amino acids,

and tyrosine kinases add phosphates to tyrosine amino acids.

Apparently, CAL-101 is a reversible inhibitor of the delta

isoform of PI3K.

http://mct.aacrjournals.org/content/8/1/1.full.html,

Mol Cancer Ther 2009;8(1):1-9, which discusses CAL-101,

indicates:

" PX-866 is the only irreversible PI3K inhibitor

currently being developed clinically............. "

Al Janski