L08_ss1_2013_462a

Application io 0 n c h r to the amide group the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ibrous IZ of synthetic polypeptides. Moreover, ani.23 we have studied. A letter the The Nobel Prize in and globular proteins, as well as resonance Chemistry 1954 "for his nouncing their discovery was published last year. ' theory is now so well The problem that weCV/ have set ourselves is that and its experimental subgrounded of finding all hydrogenresearch into the nature of bonded structures for a single polypeptide chain, in so extensive that there 1o stantiation which the residues are H N 120° can be no doubt whatever about its the chemical bond and its 120O application to the elucidation of the structure of complex substances". application io 0 N C° H R to the amide group. The observed C-N distance, 1.32 iA, corresponds to nearly 50 per cent double-bond character, and we may conclude that rotation by as much as 100 from the planar configuration would result in instability by about 1 kcal. mole-'. The interatomic PepCde Bond: Cis ­Trans IsomerizaCon •  Cα carbons on same (cis) or opposite (trans) sides of “double” bond (pepCde bond) •  Trans configuraCon highly favored (steric) ≈ 99% R group Cα Cα Cα Cα R group •  ExcepCon: X ­Pro (pepCde bonds preceding Pro residues), some of which are cis… why? Berg et al., Fig. 2-24 94% 6% Backbone torsion/dihedral angles •  PolypepCde backbones can be described by their “torsion angles” or “dihedral angles” – ...
View Full Document

Ask a homework question - tutors are online