Phosphoinositide-specific phospholipase Cs (PI-PLCs) are critical regulatory enzymes in eukaryotes which are proximal targets of activation by receptor tyrosine kinases and by G-protein-coupled receptors. We have expressed, crystallized, and determined the structure of the three-domain core of rat phosphoinositide-specific phospholipase C-delta1 at 2.4 Angstroms resolution in the triclinic crystal form. The stereochemical relationship between the three domains is essentially identical in two different crystal forms. The Ca2+ analogue Sm3+ binds at two sites between the jaws of the C2 domain. Sm3+ binding triggers a conformational change in which sections of the C2 jaws move apart, opening the mouth by 9 Angstroms and creating a gap large enough to bind a phospholipid headgroup. 3-isopropylmalate dehydrogenase (IMDH) and isocitrate dehydrogenase (IDH) belong to a unique class of metal-dependent decarboxylating dehydrogenases. A. M. Dean has fully altered the specificity of NADP+- dependent IDH in favor of NAD+ by mutagenesis, and also inverted the specificity of NAD+-dependent IMDH. We have determined the structures of both the engineered IDH and the IMDH in complex with NAD+ and NADP+, respectively. The structure of redesigned IMDH illustrates the successful creation of a new 2'-phosphate binding site. The structure of the engineered NAD+-specific IDH shows that NADP+ affinity is destroyed by removing favorable interactions and by adding a repulsive interaction with Asp344. The specificity change requires a series of changes in steric packing interactions. The linchpin for repacking in the adenosine binding site is residue 351. The side-chain of this """"""""second layer"""""""" residue dictates packing of the surrounding """"""""first layer"""""""" residues which interact with the 2' moiety and, in turn, directly determine specificity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Intramural Research (Z01)
Project #
1Z01DK036118-03
Application #
2573118
Study Section
Special Emphasis Panel (LMB)
Project Start
Project End
Budget Start
Budget End
Support Year
3
Fiscal Year
1996
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Yadav, Umesh C S; Srivastava, Satish K; Ramana, Kota V (2012) Prevention of VEGF-induced growth and tube formation in human retinal endothelial cells by aldose reductase inhibition. J Diabetes Complications 26:369-77
Kalariya, Nilesh M; Shoeb, Mohammad; Ansari, Naseem H et al. (2012) Antidiabetic drug metformin suppresses endotoxin-induced uveitis in rats. Invest Ophthalmol Vis Sci 53:3431-40
Pandey, Saumya; Srivastava, Satish K; Ramana, Kota V (2012) A potential therapeutic role for aldose reductase inhibitors in the treatment of endotoxin-related inflammatory diseases. Expert Opin Investig Drugs 21:329-39
Srivastava, Satish K; Yadav, Umesh C S; Reddy, Aramati B M et al. (2011) Aldose reductase inhibition suppresses oxidative stress-induced inflammatory disorders. Chem Biol Interact 191:330-8
Reddy, Aramati B M; Tammali, Ravinder; Mishra, Rakesh et al. (2011) Aldose reductase deficiency protects sugar-induced lens opacification in rats. Chem Biol Interact 191:346-50
Yadav, Umesh C S; Shoeb, Mohammad; Srivastava, Satish K et al. (2011) Amelioration of experimental autoimmune uveoretinitis by aldose reductase inhibition in Lewis rats. Invest Ophthalmol Vis Sci 52:8033-41
Tammali, Ravinder; Srivastava, Satish K; Ramana, Kota V (2011) Targeting aldose reductase for the treatment of cancer. Curr Cancer Drug Targets 11:560-71
Yadav, Umesh C S; Shoeb, Mohammed; Srivastava, Satish K et al. (2011) Aldose reductase deficiency protects from autoimmune- and endotoxin-induced uveitis in mice. Invest Ophthalmol Vis Sci 52:8076-85
Tammali, Ravinder; Reddy, Aramati B M; Srivastava, Satish K et al. (2011) Inhibition of aldose reductase prevents angiogenesis in vitro and in vivo. Angiogenesis 14:209-21
Shoeb, Mohammad; Yadav, Umesh C S; Srivastava, Satish K et al. (2011) Inhibition of aldose reductase prevents endotoxin-induced inflammation by regulating the arachidonic acid pathway in murine macrophages. Free Radic Biol Med 51:1686-96

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