Solution conformation of poly(L-lysyl-L-glutamic acid) and poly(L-lysyl-L-glutamine).
Solution conformation of poly(L-lysyl-L-glutamic acid) (PLGU) and poly(L-lysyl-L-glutamine) (PLGN) was studied in water as a function of pH, added salt, detergents, methanol and trifluoroethanol (TFE). Both the polypeptides exhibit no ordered conformation in the pH range 1.5-12.5; salts and detergents did not have any marked effect. Replacement of side chain carboxyl by an amide group did not help in inducing PLGN to adopt a helical conformation even at pH as high as 12.0, unlike poly(L-lysine). The helicogenic solvents, methanol and TFE, induce formation of weak helices in PLGU as well as in PLGN. It is not unlikely that H-bonding between the side chains leads to stabilizing an unordered conformations.
D002942:Circular Dichroism; D007202:Indicators and Reagents; D009904:Optical Rotation; D010455:Peptides / Q000138:chemical synthesis; D011099:Polyglutamic Acid / Q000138:chemical synthesis / Q000031:analogs & derivatives; D011107:Polylysine / Q000138:chemical synthesis / Q000031:analogs & derivatives; D011487:Protein Conformation; D012996:Solutions; D013329:Structure-Activity Relationship
D007202:Indicators and Reagents; D010455:Peptides; D012996:Solutions; D011107:Polylysine; D011099:Polyglutamic Acid; C030391:poly(glutamic acid-lysine); C042695:poly(lysly-glutamine)