scholarly journals A Strong Infra-Red Radiation from Molecular Nitrogen in the Night Sky

1944 ◽  
Vol 66 (7-8) ◽  
pp. 225-226 ◽  
Author(s):  
Joel Stebbins ◽  
A. E. Whitford ◽  
P. Swings
Keyword(s):  
Molecular Nitrogen ◽  
Infra Red ◽  
Night Sky ◽  
Red Radiation

Model of a folded polypeptide chain

1950 ◽  
Vol 137 (886) ◽  
pp. 79-79
Keyword(s):  
Amino Acid ◽  
Polypeptide Chain ◽  
Molecular Model ◽  
Polymer Chains ◽  
Side Chains ◽  
Amino Acid Residues ◽  
Infra Red ◽  
New Type ◽  
Folded Proteins ◽  
Red Radiation

The models on view in the ante-room show a way of folding a polypeptide chain which is consistent with some observations we have recently made with polarized infra-red radiation (Ambrose & Hanby 1949; Ambrose, Elliott & Temple 1949). The α -folded proteins, keratin, myosin and tropomyosin, have been found when oriented to show greater absorption of the N-H frequency when the electric vector of the absorbed radiation is in the direction of the fibre axis, hence the N-H bond must be preferentially oriented in this direction. A study of models has suggested that the only likely folding of the polypeptide chain consistent with this fact involves a seven-membered ring containing two amino-acid residues; the ring is completed by hydrogen bonds: A new type of atomic model which has been developed in our laboratories has been used. The scale is 0·8 in. to the Angstrom unit. The valency links, while allowing free rotation about single co-valent bonds, also allow some distortion of the bond angles when strains occur but are strong enough to allow long polymer chains to be built. The molecular model exhibited shows twenty-four amino-acid residues, with side chains on one side of the back-bone, representative of those occurring in myosin; the side chains on the other side have been removed for clearness and their positions indicated by single carbon atoms.

Sign in / Sign up

Export Citation Format

Share Document