final post

Fructose1,6-bisphosphatase is a simple but elegant protein. Fructose1,6-bisphosphatase has been studied for a while because it is essential part of gluconeogenesis, which is the formation of glucose from smaller molecules. Fructose1,6-bisphosphatase converts fructose 1,6-bisphosphate to fructose 6-phosphate, by removal of a phosphate.This allows it to continue to the next steps until it is converted into glucose. This reaction might seem small and unimportant, however this enzyme is critical for controlling glucose levels in the body. Without it and gluconeogenesis, blood sugar would be harder to control.

http://pubs.acs.org.lib-proxy.calvin.edu/doi/pdf/10.1021/bi00041a002

One of the important structural features of fructose 1,6-bisphosphatase has multiple subunits that allows it to change from R state to T state.  The dimers shift 17 degrees from each other. This change the Arg-22 residue to go from interacting with Glu-108 and Arg-110 to Thr-27 and Glu-29. To see if the arginine was important part of the protein functionality, researchers at Boston College converted it to an alanine. They looked at the differences in the catalytic ability of R-state vs. T state. Through their research they found that the Arg22 to Ala has no effect on the enzyme and the R-state of the enzyme enhances catalytic potential. This research shows that the arginine is only part of the catalytic properties of the enzyme.

Figure1. (a)TheFBPaseisahomotetramer.Thethreepotentialtargets are shown: (1) the active site of FBPase, (2) the allosteric binding site of AMP, (3) the tetrameric allosteric inhibitor site. PDB coordinates 1KZ813,14 were used. The figure was drawn using POVScript+.37 (b) A closeup of the AMP binding pocket is shown. The three programs used are Dock6, Autodock4, and Surflex and were tested using the crystallographic ligand AMP moved out of the binding pocket (as explained in results section). This figure was drawn using POV- Script+.37 The three conformers of AMP were superimposed with a rmsd of <2.0 Å5 from actual AMP atoms in the crystallographic structure.

http://pubs.acs.org.lib-proxy.calvin.edu/doi/pdf/10.1021/jm800720a

With an increase of obesity, fructose1,6-bisphosphatase may be a target for controlling diabetes. There are three targets that researchers at the University of Massachusetts are looking at, as seen in the figure, the active site, the allosteric binding site of AMP, and the tetrameric allosteric binding site. They have found that there are three heterocyclic organofluorine lead compounds. 

Fructose1,6-bisphosphatase may seem simple and not very significant, however it is a fascinating enzyme that plays an important part in the regulation of our blood sugar. Without it our bodies would have a difficult time keeping enough sugar in our blood.

Joseph Mendicino,* Fredrich Leibach, and Sesha Reddy, 1978 "Role of Enzyme Interactions in the Regulation of Gluconeogenesis: Phosphorylation of Fructose 1,6-Bisphosphataseand Phosphofructokinase by Kidney Protein Kinase?"

http://pubs.acs.org.lib-proxy.calvin.edu/doi/pdf/10.1021/bi00615a012

Aleksandra Rudnitskaya, Ken Huynh, Be ́la To ̈ro ̈k,* and Kimberly Stieglitz*

Novel Heteroaromatic Organofluorine Inhibitors of Fructose-1,6-bisphosphatase

http://pubs.acs.org.lib-proxy.calvin.edu/doi/pdf/10.1021/jm800720a

Guqiang Lu, Mark K. Williams, Eugene L. Giroux, and Evan R. Kantrowitz"

Fructose-1,6-bisphosphatase: Arginine-22 Is Involved in Stabilization of the T Allosteric State?

http://pubs.acs.org.lib-proxy.calvin.edu/doi/pdf/10.1021/bi00041a002

1. This article is from 1978. It is a rather old article but it looks at the regulation of gluconeogenesis by fructose 1,6-bisphosphatase and other enzymes in the kidney. This paper basically talks about the process of glucose regulation. They looked at the affects of phosphorylation on several of enzymes and determined that phosphorylation did not affect the activity of fructose 1,6-bisphosphatase. They found that it had no allosteric effects of phosphorylation on this enzyme. It is interesting to see how they discovered the affects of phosphorylation on enzymes back in the late 70's and how the basic principles still are in practice today.

Joseph Mendicino,* Fredrich Leibach, and Sesha Reddy, 1978 "Role of Enzyme Interactions in the Regulation of Gluconeogenesis: Phosphorylation of Fructose 1,6-Bisphosphataseand Phosphofructokinase by Kidney Protein Kinase?"

http://pubs.acs.org.lib-proxy.calvin.edu/doi/pdf/10.1021/bi00615a012

2. The inhibition of Fructose 1,6-bisphosphatase is maybe a form of controlling diabetes. Fructose 1,6-bisphosphatase is one of the enzymes used in the synthesis of glucose. They looked at three possible inhibitor points: 1. the active site for 1,6-bisphosphatase, 2. An allosteric binding site for AMP, and 3. A tetrameric binding site at the dimer interface. The leading compounds for inhibiting fructose 1,6-bisphosphates is organofluorines. Through this  research they found three inhibitors. It is a really interesting that  an inhibitor of this protein can help treat diseases like diabetes. 

Aleksandra Rudnitskaya, Ken Huynh, Be ́la To ̈ro ̈k,* and Kimberly Stieglitz*

Novel Heteroaromatic Organofluorine Inhibitors of Fructose-1,6-bisphosphatase

http://pubs.acs.org.lib-proxy.calvin.edu/doi/pdf/10.1021/jm800720a

3. Fructose 1,6-bisphosphatase has multiple subunits that allows it to change from R state to T state. This paper looks at the conformational change of the protein. The dimers shift 17 degrees from each other. This change the Arg-22 residue to go from interacting with Glu-108 and Arg-110 to Thr-27 and Glu-29. To see if the arginine was important part of the protein functionality, they converted it to an alanine. They looked at the differences in the catalytic ability of R-state vs. T state. Through their research they found that the Arg22 to Ala has no effect on the enzyme and the R-state enhances catalytic potential. This research shows that the arginine is only part of the catalytic properties of the enzyme. 

Guqiang Lu, Mark K. Williams, Eugene L. Giroux, and Evan R. Kantrowitz"

Fructose-1,6-bisphosphatase: Arginine-22 Is Involved in Stabilization of the T Allosteric State?

http://pubs.acs.org.lib-proxy.calvin.edu/doi/pdf/10.1021/bi00041a002

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