NOE data at 500 MHz reveal the proximity of phenyl and tyrosine rings in enkephalin

FEBS Letters

Sarma, R.H.¹  Gupta, Goutam¹  Dhingra, M.M.²  Sarma, M.H.¹ 

[1] Institute of Biomolecular Stereodynamics, State University of New York at Albany, Albany, NY 12222, USA;Chemical Physics Division, Tata Institute of Fundamental Research, Homi Bhabha Road, Bombay 400005, India

关键词: Nuclear Overhauser effect;    Enkephalin;    Met5-enkephalin;    Conformation;   

DOI  :  10.1016/0014-5793(86)80414-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Met⁵-enkephalin - a pentapeptide (Tyr-Gly-Gly-Phe-Met) - can exist in two possible folded arrangements with a rigid two-hydrogen-bonded network. In one arrangement, a Gly 2-Gly 3 β-bend is formed and in the other a Gly 3-Phe 4 β-bend. The two conformations are distinguished by the spatial relation of Tyr 1 and Phe 4: in the Gly 2-Gly 3 β-bend, Tyr 1 and Phe 4 can be brought close to each other while in the Gly 3-Phe 4 β-bend they are far apart (⪢5 Å). We have utilized one-dimensional (1D) nuclear Overhauser effect (NOE) measurements between the ring protons of Tyr 1 and Phe 4 to determine their proximity. The NOE data clearly show that a pair protons, one each from Tyr 1 and Phe 4, are as close as 3.3 Å while other inter-proton distances are beyond 4.5 Å. Therefore, we propose the presence of a Gly 2-Gly 3 β-bend (in which Tyr 1 and Phe 4 are spatially close) for Met⁵-enkephalin in solution. The structure of Met⁵-enkephalin in solution is very similar to the single crystal structure of Leu⁵-enkephalin and tends to explain the biological activity data of several modified enkephalins.

【 授权许可】

Unknown