Proline iyo glycine waxaa mararka qaarkood loo yaqaanaa "burinaya helix" sababtoo ah waxay carqaladeeyaan joogteynta qaab dhismeedka lafdhabarta ee α; si kastaba ha ahaatee, labaduba waxay leeyihiin awood aan caadi ahayn oo qaab dhismeedka ah waxaana caadi ahaan laga helaa wareegyo. Amino acids oo doorbidaya inay qaataan qaababka helical ee borotiinka waxaa ka mid ah methionine, alanine, leucine, glutamate iyo lysine ("MALEK" ee amino-acid 1-xaraf codes); taas bedelkeeda, haraagaha aromatic ee waaweyn (tryptophan, tyrosine iyo phenylalanine) iyo amino acids-ka Cβ-laabadaysan (isoleucine, valine, iyo threonstrine) waxay doorbidaan inay qaataan β-andine doorbid. Si kastaba ha noqotee, doorbidayaashaan kuma filna inay keenaan hab lagu kalsoonaan karo oo lagu saadaalin karo taxanaha qaab dhismeedka labaad iyadoo la adeegsanayo habkan. Su'aal: Waa maxay noo
qaab dhismeedka labaad