Proposed folding pattern for apolipoprotein A-II based on a structural analogy with uteroglobin.
The tertiary structure observed in the crystalline state for uteroglobin, a small steroid binding protein, is used as a template to build an approximated model for apolipoprotein A-II. The presence of four proline residues and four hydrophobic clusters located at similar positions in apolipoprotein A-II and uteroglobin is taken as the major source of stability in such tertiary structures. A brief description of plausible specific binding sites appearing on the model of apolipoprotein A-II is given. It is suggested that the internal cavity and the four surface pockets observed for uteroglobin and postulated for apolipoprotein A-II might be used to insure specific binding of triglycerides, phospholipids, or cholesterol.
D000818:Animals; D016633:Apolipoprotein A-II; D001054:Apolipoproteins A / Q000378:metabolism; D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D002784:Cholesterol / Q000378:metabolism; D003460:Crystallization; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism; D008958:Models, Molecular; D010743:Phospholipids / Q000378:metabolism; D011487:Protein Conformation; D011817:Rabbits; D013698:Templates, Genetic; D014280:Triglycerides / Q000378:metabolism; D014598:Uteroglobin / Q000378:metabolism
D016633:Apolipoprotein A-II; D001054:Apolipoproteins A; D006023:Glycoproteins; D008075:Lipoproteins, HDL; D010743:Phospholipids; D014280:Triglycerides; D014598:Uteroglobin; D002784:Cholesterol