Differentiated analysis of the secondary structure of hydrophilic and hydrophobic regions in α‐ and β‐subunits of Na+,K+‐ATPase by Raman spectroscopy

FEBS Letters

Arzamazova, N.M.¹  Modyanov, N.N.¹  Ovchinnikov, Yu.A.¹  Arystarkhova, E.A.¹  Dzhandzhugazyan, K.N.¹  Nabiev, I.R.¹  Efremov, R.G.¹ 

[1] Shemyakin Institute of Bioorganic Chemistry, USSR Academy of Sciences, 117871 Moscow, USSR

关键词: (Na+ + K+)-ATPase;    Raman spectroscopy;    Secondary structure;   

DOI  :  10.1016/0014-5793(88)80905-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Raman spectra of active Na⁺,K⁺-ATPase from pig kidney and membrane-bound products of its two-stage trypsinolysis, including α-subunit hydrophobic regions as well as the intact β-subunit and hydrophobic regions of α- and β-subunits, were measured to calculate the secondary structure of hydrophilic and hydrophobic regions of the enzyme. Consequent comparison demonstrated unambiguously that (i) membrane-bound hydrophobic parts of polypeptide chains of Na⁺,K⁺-ATPase subunits are in the α-helical conformation; (ii) essential contents of the α-helix as well as β-sheet are estimated to form the hydrophilic (mainly cytoplasmic) domain of the Na⁺,K⁺-ATPase α-subunit; (iii) the exoplasmic hydrophilic domain of the β-subunit is shown to include several antiparallel β-pleated sheets and a small amount of the α-helix and unordered conformations. The model of the secondary structure organization of hydrophilic domains as well as 8 hydrophobic transmembrane segments of the enzyme molecule was proposed on the basis of experimental results and predictional calculations.

【 授权许可】

Unknown