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Hydrophilic residue

The sequence space of proteins is extremely dense. The number of possible protein sequences is 20. It is clear that even by the fastest combinatorial procedure only a very small fraction of such sequences could have been synthesized. Of course, not all of these sequences will encode protein stmctures which for functional purjDoses are constrained to have certain characteristics. A natural question that arises is how do viable protein stmctures emerge from the vast sea of sequence space The two physical features of folded stmctures are (l)in general native proteins are compact but not maximally so. (2) The dense interior of proteins is largely made up of hydrophobic residues and the hydrophilic residues are better accommodated on the surface. These characteristics give the folded stmctures a lower free energy in comparison to all other confonnations. [Pg.2646]

Figure 3 The mimmum energy conformation of the off-lattice 46-mer P-baiTel model. Hydrophobic residues are in gray, hydrophilic residues in black, and neutral residues are white. (Adapted from Ref. 44.)... Figure 3 The mimmum energy conformation of the off-lattice 46-mer P-baiTel model. Hydrophobic residues are in gray, hydrophilic residues in black, and neutral residues are white. (Adapted from Ref. 44.)...
Loop regions exposed to solvent are rich in charged and polar hydrophilic residues. This has been used in several prediction schemes, and it has proved possible to predict loop regions from an amino acid sequence with a higher degree of confidence than a helices or p strands, which is ironic since the loops have irregular structures. [Pg.21]

We thus have here a case where a mutation on the surface of the globin fold, replacing a hydrophilic residue with a hydrophobic one, changes important properties of the molecule and produces a lethal disease. Why has the... [Pg.44]

The bulk of the hydrophilic residues of the p subunit are exposed on the extra-... [Pg.10]

The transition enthalpies of the s- and p-fractions obtained from the feed with a comonomer molar ratio of 85 15 were equal to 6 and 7 J/g, respectively, i.e. the values are very close. This, therefore, can be indicative of almost the same average length of oligoNVCl blocks. Moreover, as we have already stressed, the fractions also had virtually the same final comonomer composition. However, since the solution properties of these fractions are drastically different, one can draw the conclusion that this is apparently due to a specific distribution of hydrophobic and hydrophilic residues along the polymer chains. In turn, because of all the properties that are exhibited by the s-fraction, this fraction can be considered to be a protein-like copolymer [27]. [Pg.119]

The structural solution for the vast majority of OM proteins is provided in the form of the (3-strand, a secondary fold, which allows portions of the polypeptide chain to organise as a (3-barrel. In this cylindrical structure, hydro-phobic residues point outwards and hydrophilic residues are located inside, which can allow the formation of a water-filled channel [30 33]. [Pg.279]

Figure 19.12 Water helps to stabilize collagen by forming inter- and intra-hydrogen bonds with hydrophilic residues. (From Nyman et al., 2005. Copyright 2003, with permission from Elsevier.)... Figure 19.12 Water helps to stabilize collagen by forming inter- and intra-hydrogen bonds with hydrophilic residues. (From Nyman et al., 2005. Copyright 2003, with permission from Elsevier.)...
The peptide chain in globular proteins is folded into fairly compact conformations. Water-soluble enzymes are typical globular proteins which have most of the hydrophobic amino acid residues located in the interior and the hydrophilic residues located mainly at the surface in contact with solvent water. The average radii are 20-40 A (Boyer, 1970). It is clear that there are common morphological features between surfactant micelles and enzyme molecules. This fact has prompted many chemists to use micelles as enzyme models. However, it must be emphasized that micelles exist in dynamic equilibria with monomeric surfactant and their hydrophobic core is quite fluid, whereas enzyme molecules have precisely fixed three-dimensional structures. [Pg.437]

Symmetric amphiphilic molecules, in which two hydrophilic residues are linked by hydrophobic segments, are generally known as bola-lipids based on their resemblance to an old South American hunting weapon. Well-characterized bola amphiphiles are archaebacterial lipids, which usually consist of two glycerol backbones connected by two hydrophobic... [Pg.325]

The 1.6 A-resolution crystal structure of the muscle al subunit extracellular domain revealed an unexpected water molecule in the core of the al nAChR subunit, in the vicinity of the transmembrane domain (Dellisanti et al. 2007). This is surrounded by hydrophilic residues that are conserved in nAChR subunits, but absent from the AChBR The water molecule confers flexibility, making the non-optimally... [Pg.177]

The van der Waals model of monomeric insulin (1) once again shows the wedge-shaped tertiary structure formed by the two chains together. In the second model (3, bottom), the side chains of polar amino acids are shown in blue, while apolar residues are yellow or pink. This model emphasizes the importance of the hydrophobic effect for protein folding (see p. 74). In insulin as well, most hydrophobic side chains are located on the inside of the molecule, while the hydrophilic residues are located on the surface. Apparently in contradiction to this rule, several apolar side chains (pink) are found on the surface. However, all of these residues are involved in hydrophobic interactions that stabilize the dimeric and hexameric forms of insulin. [Pg.76]

These proteins are often globular in shape so as to offer a different look or polar nature to their outside. Hydrophobic residues are generally found in the interior while hydrophilic residues are found on the surface interacting with the hydrophilic water-intense external environment. (This theme is often found for synthetic polymers that contain both polar and nonpolar portions. Thus, when polymers are formed or reformed in a regular water-filled atmosphere, many polymers will favor the presence of polar moieties on their surface.)... [Pg.313]

Where is it most likely to find a hydrophobic amino acid—on the surface of a protein or buried in the interior —Same question for a hydrophilic residue. [Pg.305]

A hydrophobic amino acid will most likely be found in the hydrophobic core—a hydrophilic residue will (at least for water soluble proteins) most likely be located on the surface. [Pg.306]


See other pages where Hydrophilic residue is mentioned: [Pg.2655]    [Pg.2660]    [Pg.562]    [Pg.564]    [Pg.202]    [Pg.562]    [Pg.35]    [Pg.69]    [Pg.231]    [Pg.515]    [Pg.15]    [Pg.153]    [Pg.458]    [Pg.265]    [Pg.23]    [Pg.82]    [Pg.89]    [Pg.276]    [Pg.179]    [Pg.210]    [Pg.198]    [Pg.426]    [Pg.334]    [Pg.233]    [Pg.201]    [Pg.211]    [Pg.218]    [Pg.226]    [Pg.461]    [Pg.95]    [Pg.21]    [Pg.77]    [Pg.60]    [Pg.370]    [Pg.270]   
See also in sourсe #XX -- [ Pg.72 ]

See also in sourсe #XX -- [ Pg.60 ]




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Hydrophilic amino acid residues

Hydrophilic and hydrophobic residues

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