Amino terminus Carboxyl termin Transmission of electric dipole in a-helix
Transmission of electric dipole in a-helix
2.2.8 Five constraints affecting the sta bility of a-helix The electrostatic repulsion(or attraction) between successive Aa residues with charged r groups; The bulkiness of adjacent r groups; The interactions between AA side chains spaced three(or four) residues apart The occurrence of Pro and gly residues The interaction between Aa residues at the ends of the helical segment and the electric dipole inherent to the a helix
2.2.8 Five constraints affecting the stability of a-helix •The electrostatic repulsion (or attraction) between successive AA residues with charged R groups; •The bulkiness of adjacent R groups; •The interactions between AA side chains spaced three (or four) residues apart; •The occurrence of Pro and Gly residues; •The interaction between AA residues at the ends of the helical segment and the electric dipole inherent to the a helix
23β- pleated sheet(orβ conformation)was proposed to be the more extended conformation of the polypeptide chain. 2.3.1 The conformation is formed when two or more almost fully extended polypeptide chains are brought together side by side 2.3.2 Regular hydrogen bonds are formed between the carbonyl oxygen and amide hydrogen between adjacent chains (look like a zipper 2.3.3 The axial distance between the adjacent amino acid residues is 3.5 Angstroms
2.3 b-pleated sheet (or b conformation) was proposed to be the more extended conformation of the polypeptide chain. 2.3.1 The conformation is formed when two or more almost fully extended polypeptide chains are brought together side by side. 2.3.2 Regular hydrogen bonds are formed between the carbonyl oxygen and amide hydrogen between adjacent chains (look like a zipper). 2.3.3 The axial distance between the adjacent amino acid residues is ~3.5 Angstroms
23. 4 The planes of the peptide bonds arrange as pleated sheets. 2.3.5 The r groups of adjacent residues protrude in opposite directionS. 23. 6 The adjacent polypeptide chains can be either parallel (the same direction or antiparallel (the opposite direction)
2.3.4 The planes of the peptide bonds arrange as pleated sheets. 2.3.5 The R groups of adjacent residues protrude in opposite directions. 2.3.6 The adjacent polypeptide chains can be either parallel (the same direction) or antiparallel (the opposite direction)