Backbone Structure and Dynamics of a Hemolymph Protein from the Mealworm Beetle Tenebrio molitor
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- 作者：Sven Rothemund ; Yih-Cherng Liou ; Peter L. Davies ; and Frank D. Sö ; nnichsen
- 刊名：Biochemistry
- 出版年：1997
- 出版时间：November 11, 1997
- 年：1997
- 卷：36
- 期：45
- 页码：13791 - 13801
- 全文大小：232K
- 年卷期：v.36,no.45(November 11, 1997)
- ISSN：1520-4995
文摘
Pheromones play a vital role in the survival of insectsand are used for chemical communicationbetween members of the same species by their olfactory system. Theselection and transportation ofthese lipophilic messengers by carrier proteins through the hydrophilicsensillum lymph in the antennaetoward their membrane receptors remains the initial step for the signaltransduction pathway. A moderatelyabundant 12.4 kDa hydrophilic protein present in hemolymph from themealworm beetle Tenebrio molitoris ~38% identical to a family of insect pheromone-binding proteins.The backbone structure and dynamicsof the 108-residue protein have been characterized usingthree-dimensional 1H-15N NMRspectroscopy,combined with 15N relaxation and 1H/D exchangemeasurements. The secondary structure, derived fromcharacteristic patterns of dipolar connectivities between backboneprotons, secondary chemical shifts,and homonuclear three-bond JHNH
coupling constants, consists of a predominantly disorderedN-terminusfrom residues 1 to 10 and six -helices connected by four 4-7residue loops and one 
-hairpin structure.The up-and-down arrangement of -helices is stabilized by twodisulfide bonds and hydrophobic interactionsbetween amphipathic helices. The backbone dynamics werecharacterized by the overall correlation time,order parameters, and effective correlation times for internal motions.Overall, a good correlation betweensecondary structure and backbone dynamics was found. The15N relaxation parameters T1 andT2 andsteady-state NOE values of the six -helices could satisfactorily fitthe Lipari-Szabo model. In agreementwith their generalized order parameters (>0.88), residues in helicalregions exhibited restricted motionson a picosecond time scale. The stability of this highly helicalprotein was confirmed by thermaldenaturation studies.
coupling constants, consists of a predominantly disorderedN-terminusfrom residues 1 to 10 and six -helices connected by four 4-7residue loops and one -hairpin structure.The up-and-down arrangement of -helices is stabilized by twodisulfide bonds and hydrophobic interactionsbetween amphipathic helices. The backbone dynamics werecharacterized by the overall correlation time,order parameters, and effective correlation times for internal motions.Overall, a good correlation betweensecondary structure and backbone dynamics was found. The15N relaxation parameters T1 andT2 andsteady-state NOE values of the six -helices could satisfactorily fitthe Lipari-Szabo model. In agreementwith their generalized order parameters (>0.88), residues in helicalregions exhibited restricted motionson a picosecond time scale. The stability of this highly helicalprotein was confirmed by thermaldenaturation studies.