Spectroscopic evidence revealing polyproline II structure in hydrophobic, putatively elastomeric sequences encoded by specific exons of human tropoelastin.
Elastin, the protein responsible for tissue elasticity, is contained in arterial walls, lungs, and skin. Given the cassette like organization of the human tropoelastin gene, giving rise to alternating exons encoding for crosslink domains and elastomeric domains, it is tempting to suggest that polypeptides encoded by different exons could adopt structures independent of the other exons. The results obtained with the polypeptide sequences encoded by exons 3, 7, and 30 of human tropoelastin are described. It is shown that these hydrophobic exons may partly assume the polyproline II (PPII) structure, as found by circular dichroism studies in aqueous solution. Classical Raman spectroscopy evidences a specific sharp band at 1314 cm(-1), which is assigned to the PPII structure adopted by these exons in the solid state. As these sequences are among those putatively responsible for elastomeric properties, these findings are of particular interest in relation to the current models of the elasticity of elastin.
Laboratoire de Spectroscopies et Structures Biomoléculaires, LSSBM EA-3305, Université de Reims Champagne-Ardenne, IFR 53 Biomolécules, UFR Sciences Exactes et Naturelles, BP 1039, 51687 Reims Cedex 2, France.
Brigida
B
Bochicchio
Amina
A
Aït-Ali
Antonio M
AM
Tamburro
Alain J P
AJ
Alix
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004548:Elasticity; D004549:Elastin / Q000737:chemistry; D020724:Elastomers; D005091:Exons; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D010455:Peptides / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary / Q000235:genetics; D013059:Spectrum Analysis, Raman; D013329:Structure-Activity Relationship; D014333:Tropoelastin / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics*; D014867:Water / Q000737:chemistry
D020724:Elastomers; D010455:Peptides; D011108:Polymers; D014333:Tropoelastin; C036925:elastomeric polymer; D014867:Water; C011083:polyproline; D004549:Elastin