>Parallel sheets are less twisted than antiparallel and are always
>buried. In contrast, antiparallel sheets can withstand greater distortions
>(twisting and beta-bulges) and greater exposure to solvent. This implies
>that antiparallel sheets are more stable than parallel ones which is
>consistent both with the hydrogen bond geometry and the fact that small
>parallel sheets rarely occur (see above).
BUT, isn't a beta-barrel a parallel beta-sheet????
AND, isn't a beta-barrel a common folding pattern????
FURTHERMORE, as a beta-barrel satisfies the hydrogen-bonding of all
the beta-strands, isn't it more stable than an anti-parallel sheet
with the same number of strands????
-Pete