Protein structure investigations

Fibrous protein structure investigations applying X-ray diffraction and electron microscopy were reviewed by Blakely (31). Keratin fibers are made of three main structural components the cuticle, the cortex, and the medulla. The medulla is only present in coarse fibers. The cortex forms the bulk of the fiber. Various morphological models have been proposed to explain the mechanical properties of keratin fibers. It is generally agreed that the cortex consists of fibrils in which protein molecules exist in helical and nonhelical regions. 

Mass spectrometrie techniques that include continuous flow fast atom bombardment (FAB), electrospray ionization (ESI), and matrix assisted laser desorption (MALDI) have been applied successfully to protein structure investigations. (3) The hyphenation of electrospray ionization mass... 

We are grateful to Dr. Azat Badretdinov and Mr. Eric Feyfant for many discussions about comparative protein structure modeling. AF is a Burroughs Wellcome Fellow. RS is a Howard Hughes Medical Institute predoctoral fellow. FM is a Norman and Rosita Winston Biomedical Research Foundation Fellow. AS is a Sinsheimer Scholar and an Alfred P. Sloan Research Fellow. The investigations have also been aided by grants from NIH (GM 54762) and NSF (BIR-9601845). 

The information obtained from X-ray measurements on the arrangement of the water molecules naturally depends very much on the resolution and state of refinement of the crystal structure investigated. For detailed information on the organization of water molecules in the protein hydration shell at the surface and on the bulk water in the crystals a 1,2 to 1,8 A resolution range is necessary 153>. 

These are exciting times for peptide based materials. The number of investigators in this field and consequently the number of publications in this area have increased tremendously in recent years. Not since the middle of the past century has there been so much activity focused on the physical properties of peptidic materials. Then, efforts were focused on determination of the fundamental elements that make up protein structures, leading to the discoveries of the a—helix and the (3-sheet. Many years of study followed where the propensities of individual and combinations of amino acids to adopt and stabilize these structures were investigated. Now, this knowledge is being applied to the preparation, assembly, and use of peptide based materials with designed sequences. This volume summarizes recent developments in all these areas. 

H. A. Havel, R. S. Chao, R. J. Haskell, and T. J. Thamann. Investigation of protein structure with optical spectroscopy Bovine growth hormone, Anal. Chem., 61, 642 (1989). 

Kelly SM, Price NC. The use of circular dichroism in the investigation of protein structure and function. Curr. Protein Pept. Sci. 2000 1 349-384. 

Certain bifunctional metal chelating agents have been used to investigate protein interactions by virtue of their ability to generate reactive oxygen species that affects protein structure in the immediate vicinity of their modification site. The following sections discuss two applications of such chelate labels, one of which cleaves peptide bonds while the other one causes covalent crosslinks to occur between interacting protein structures. 

The sorbent materials are supplied as finely dispersed colloidal particles, whose surfaces are smooth. Some of their properties are presented in Table 3. The sorbents cover different combinations of hydrophobicity and sign of the surface charge. Thus, the model systems presented allow systematic investigation of the influences of hydrophobicity, electric charge, and protein structural stability on protein adsorption. 

The authors find that the CuZnSOD protein backbone (the so-called SOD rack ) remains essentially unchanged in all structures investigated here and therefore assume that backbone changes do not play a role in the catalytic cycle. 

Ras and its relatives are subjects of intensive investigations by biological, biochemical, biophysical, and medical studies. Within just one decade more than 17,000 articles (Medline, 1966-2000) deal with function and properties of this protein. Structural and functional data, based on Ras as a prototype, have provided insight into the basic principles of GTP-binding proteins, their activation, de-activation, and signal transmission. 

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