Side chains, hydrophobicity

Transport of amino acids across a chloroform liquid membrane with these carriers also revealed a high specificity (Scheme 2). For efficient transport, an aromatic side chain must be present and the distance between the aryl and ammonium functions is optimal in the P-aryl systems. Neither oe-phenyl-glycine 42 nor y-phenyl-butyrine 43 are transported to significant extents 25a>. These results are shown in Table 2. The selectivity with 13 contrasts sharply for that observed with typical detergents wherein side chain hydrophobicity determines the relative transport rates. 

Oligomers are P-sheet Hydrophobic side chain Hydrophobic interaction... 

The folding of proteins into their characteristic three-dimensional shape is governed primarily by noncovalent interactions. Hydrogen bonding governs the formation of a helices and [) sheets and bends, while hydrophobic effects tend to drive the association of nonpolar side chains. Hydrophobicity also helps to stabilize the overall compact native structure of a protein over its extended conformation in the denatured state, because of the release of water from the chain s hydration sheath as the protein... 

Major recipes for increasing the thermostability observed in previous computational sequence/stmcture analysis and con-hrmed in experiment vary from the optimization of hydrophobic core interactions (18-20) to the introduction of additional ion pairs (7, 33). Respectively, thermophilic trends knovm so far include a large difference between the proportion of charged (DEKR) versus polar (noncharged, NQST) residues (34, 35), an increase of long and branched side chain hydrophobic residues... 

Juan AS, Letoumeur D, Izumrudov VA (2(X)7) Quatemized poly(4-vinylpyridme)s as model gene delivery polycations structure-function study by modification of side chain hydrophobicity and degree of alkylation. Bioconjug Chem 18 922-928... 

J. Pato, and F. Tiidos, Polymeric prodrugs, 7. EiFect of the side chain hydrophobicity on the enzymatic hydrolysis of a polymer-bound drug model, Makromol. Chem. Rapid Commun., 10,497-502,1989. 

Table 1.15. Bitter taste of dipeptide A-B dependence of recognition threshold value (mmol/1) on side chain hydrophobicity (0 sweet or neutral taste)...

Fig. 1.51. Plastein reaction with papain incorporation rates of amino acid esters as function of side chain hydrophobicity. (according to Arai et al., 1978)...

Table 10.11. Distribution of amino acid residues with ionizing side chains (net charge) and with nonpolar side chains (hydrophobicity) in agi-casein and p-casein...

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