Ads
related to: beta turn peptides
Search results
Results From The WOW.Com Content Network
Apart from the type I, I’,II and II’ beta turns as identified via the hydrogen bond criterion, non-hydrogen-bonded beta-turns named type VIII often occur. Three other, fairly rare, types of beta turn have been identified in which the peptide bond between residues i+1 and i+2 is cis rather than trans; these are named types VIa1, VIa2 and VIb ...
At least eight forms of the beta turn occur, varying in whether a cis isomer of a peptide bond is involved and on the dihedral angles of the central two residues. The classical and inverse β-turns are distinguished with a prime, e.g. , type I and type I′ beta turns .
Beta bend ribbons may be formed from any of these types but type I is the commonest in proteins, as it is for single beta turns. Beta bend ribbons made from type I or I’ turns are somewhat twisted, while beta bend ribbons made from type II or II’ beta turns are flat. Beta bend ribbons with mixtures of different beta turn types also occur.
The most common secondary structures are alpha helices and beta sheets. Other helices, such as the 3 10 helix and π helix , are calculated to have energetically favorable hydrogen-bonding patterns but are rarely observed in natural proteins except at the ends of α helices due to unfavorable backbone packing in the center of the helix.
β-alanine, an example of a β-amino acid. The amino group attaches not to the α carbon but to the β-carbon, which in this case is a methylene group.. Beta-peptides (β-peptides) are peptides derived from β-amino acids, in which the amino group is attached to the β-carbon (i.e. the carbon two atoms away from the carboxylate group).
Chemical exfoliants like alpha hydroxy acids (AHAs) or beta hydroxy acids (BHAs) use different acids to gently slough away dead skin and encourage new cell turnover for brighter, more younger ...