Amino acid hydrophobic

Figure 10.7 The EGF receptor. The N-terminal, extracellular region of the receptor contains 622 amino acids. It displays two cysteine-rich regions, between which the ligand-binding domain is located. A 23 amino acid hydrophobic domain spans the plasma membrane. The receptor cytoplasmic region contains some 542 amino acids. It displays a tyrosine kinase domain, which includes several tyrosine autophosphorylation sites, and an actin-binding domain that may facilitate interaction with the cell cytoskeleton...

Bitterness of 0-Aminoacyl Sugars Containing Hydrophobic Amino Acids. Hydrophobic amino acids are known to produce a bitterness. Therefore, we... 

Wilce, M.C J., Aguilar, M.-L, and Heam, T.W. 1995. Physicochemical basis of amino acid hydrophobicity scales Evaluation of four new scales of amino acid hydrophobicity coefficients derived from RP-HPLC of peptides. Anal. Chem. 67 1210-1219. 

The extrinsic pathway of coagulation is activated when circulating factor VII encounters tissue factor. Tissue factor is a transmembrane glycoprotein, which is normally expressed by subendothelial fibroblast-like cells, which surround the blood vessel. An intact endothelium normally shields the circulating blood from exposure to tissue factor. The tissue factor molecule consists of a 219 amino acid hydrophilic extracellular domain, a 23 amino acid hydrophobic region that spans the membrane, and a 21 amino acid cytoplasmic tail that anchors the molecule to the cell membrane (15,16). Other sites of tissue factor expression include activated monocytes, activated endothelial cells, and atherosclerotic plaques. 

ProTherm (16) is a large collection of thermodynamic data on protein stability, which has information on 1) protein sequence and stmcture (2) mutation details (wild-type and mutant amino acid hydrophobic to polar, charged to hydrophobic, aliphatic to aromatic, etc.), 3) thermodynamic data obtained from thermal and chemical denaturation experiments (free energy change, transition temperature, enthalpy change, heat capacity change, etc.), 4) experimental methods and conditions (pH, temperature, buffer and ions, measurement and method, etc.), 5) functionality (enzyme activity, binding constants, etc.), and 6) literature. 

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Charton, M. and Charton, B.I. (1982) The structural dependence of amino acid hydrophobicity parameter. /. Theor. Biol, 99, 629-644. 

Statistical surveys on the exposure to solvent of amino acid side chains in globular proteins have been used to arrive at special amino acid hydrophobicity scales, which in turn can be used to predict the exposure of peptide segments in proteins of unknown structure. Such prediction schemes have been used successfully to identify antigenic recognition sites at the surface of proteins of unknown three-dimensional structures [16]. 

Various amino acid hydrophobicity coefficient scales derived from both chromatographic and octanol-water partition studies are listed in Table 3. Comparison of the experimentally observed retention times with those predicted from the summated hydrophobicity coefficients suggests that these approaches can in some special circumstances provide a reasonably accurate estimation of the elution profile... 

Fig. 2.1.4. Chlorsulfuron in the herbicide binding site of yeast AHAS. (a) The herbicide and nearby amino acids are shown as ball-and-stick models. The isoalloxazine ring of FAD is shown as a stick model, (b) Key contact distances (a) from chlorsulfuron to nearby amino acids. Hydrophobic contacts...

Heam and co-workers [460,461] have published a series of results relating amino acid hydrophobicity to reversed-phase retention of amino acids and peptides. The authors used wide-pore C4 or C]g columns and a gradient of IPA/acetonitrile/water (0.1% TEA) in generating results. A total of 1738 peptides covering 12 previously generated amino acid hydrophobicity scales were part of the study. Predicted and actual retention times of overlapping heptamers in myohemerythrin were presented. This study and previous studies cited therein offer excellent theoretieal and experimental bases for the predictive chromatography of amino acids and peptides. 

Biswas MK, DeVido DR, Dorsey JG, Evaluation of methods for measuring amino acid hydrophobicities and interactions. J Chromatogr A 2003 1000(1—2) 637—55. 

TABLE 18.5 Structures, Names, and Abbreviations of 20 Common Amino Acids at Physiological pH (7.4) Nonpolar Amino Acids (Hydrophobic)... 

Figure 10.7 A diagrammatic representation of modes of binding of an anionic surfactant to a protein, after Dominguez [43]. Some modes of interaction, especially hydrophobic interactions with the amino acid hydrophobic residues would be equally appropriate for non-ionic and cationic surfactants. In addition, cationic surfactants could attach themselves electrostatically to the anionic sites. The hydrophobic interactions are supported by the results of Helenius and Simons [44] which demonstrated that lipophilic proteins bound up to about 70% of their weight of deoxycholate and Triton X-lOO but that hydrophilic proteins bound little surfactant.

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