Two major modes of inductive interaction:

 Instructive interaction

 Permissive interaction

TLS Online TPP Program

#Id: 8457

#Unit 1. Molecules and their Interaction Relevant to Biology

Gly is often observed at the C-cap & N cap both positions, Pro at the Ncap and Asp and Glu at N2 and N3.

TLS Online TPP Program

#Id: 8458

#Unit 1. Molecules and their Interaction Relevant to Biology

Helix can form in polypeptides consisting of either L- or D-amino acids but never exist to contain both types.

TLS Online TPP Program

#Id: 8459

#Unit 1. Molecules and their Interaction Relevant to Biology

Five types of constraints affect the stability of an  helix: 

(1) the intrinsic propensity of an amino acid residue to form an  helix; 

(2) the interactions between R groups, particularly those spaced three (or four) residues apart; 

(3) the bulkiness of adjacent R groups; 

(4) the occurrence of Pro and Gly residues; and 

(5) interactions between amino acid residues at the ends of the helical segment and the electric dipole inherent to the  helix.

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#Id: 8460

#Unit 1. Molecules and their Interaction Relevant to Biology

The intrinsic propensity of an amino acid residue to form an  helix

TLS Online TPP Program

#Id: 8461

#Unit 1. Molecules and their Interaction Relevant to Biology

The interactions between R groups, particularly those spaced three (or four) residues apart; The assembly is said to have a coiled coil structure because each α helix itself follows a helical path.

TLS Online TPP Program

#Id: 8462

#Unit 1. Molecules and their Interaction Relevant to Biology