Proteins cooperativity and

Protein Cooperativity and Wrapping Two Themes in the Transformative Platform of Molecular Targeted Therapy... 

Perutz, M. Mechanisms of cooperativity and allosteric regulation in proteins. Cambridge Cambridge University Press, 1990. 

The study of skin irritation is probably still more complex than that of eye irritation. Surfactants interact with epidermal tissues, proteins, and enzymes causing local effects. Singer and Pittz [369], Cooper and Berner [370], and Schwuger and Bartnik [371] presented excellent explanations and reviews on these interactions. 

Perutz, M. (1990), Mechanisms of Cooperativity and Allosteric Regulation in Proteins, Cambridge University Press, New York. 

Tegoulia VA, Cooper SL (2000) Leukocyte adhesion on model surfaces under flow effects of surface chemistry, protein adsorption, and shear rate. J Biomed Mater Res 50 291-301... 

Scotchford CA, Gilmore CP, Cooper E, Leggett GJ, Downes S (2002) Protein adsorption and human osteoblast-like cell attachment and growth on alkylthiol on gold self-assembled monolayers. J Biomed Mater Res 59 84-99... 

Temperature-sensitive mutations usually arise from a single mutation s effect on the stability of the protein. Temperature-sensitive mutations make the protein just unstable enough to unfold when the normal temperature is raised a few degrees. At normal temperatures (usually 37°C), the protein folds and is stable and active. However, at a slightly higher temperature (usually 40 to 50°C) the protein denatures (melts) and becomes inactive. The reason proteins unfold over such a narrow temperature range is that the folding process is very cooperative—each interaction depends on other interactions that depend on other interactions. 

Even more interesting is the observed regioselectivity of 37 its reaction with 2, 3 -cCMP and 2, 3 -cUMP resulted in formation of more than 90% of 2 -phosphate (3 -OH) isomer. The postulated mechanisms for 37 consists of a double Lewis-acid activation, while the metal-bound hydroxide and water act as nucleophilic catalyst and general acid, respectively (see 39). The substrate-ligand interaction probably favors only one of the depicted substrate orientations, which may be responsible for the observed regioselectivity. Complex 38 may operate in a similar way but with single Lewis-acid activation, which would explain the lower bimetallic cooperativity and the lack of regioselectivity. Both proposed mechanisms show similarities to that of the native phospho-monoesterases (37 protein phosphatase 1 and fructose 1,6-diphosphatase, 38 purple acid phosphatase). 

The Natural Fibers and Food Protein Commission of Texas, Carl Cox, executive director, supported this work over an extended period of time, which is gratefully acknowledged. Additional support came from Texas Cottonseed Crushers Assoc, and Cotton, Inc. The author acknowledges and expresses appreciation for the cooperation and contributions of graduate students. The contributions of Theresa Smith and Carol Owsiany in preparing this manuscript are appreciated. 

This research was conducted with USDA funding. The authors wish to express appreciation to Dr. E. Lusas and coworkers at the Food Protein Research and Development Center, Texas A M University for their cooperative research efforts in process and product development. 

---