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Native states of adenylate kinase are two active sub‐ensembles
Author(s) -
Han Yang,
Li Xia,
Pan Xianming
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)03291-x
Subject(s) - adenylate kinase , chemistry , kinetics , stereochemistry , binding site , native state , enzyme , biophysics , biochemistry , biology , physics , quantum mechanics
There are two kinds of conformational forms of adenylate kinase (AK) in equilibrium in solution with different ANS‐binding properties. Furthermore, the nature of AP 5 A inhibition suggests also that the native forms of AK for binding with different substrates pre‐exist in the absence of substrates. In the present study, a kinetics approach was used to explore the native forms distinguished by ANS‐binding properties and by the nature of AP 5 A inhibition. The results revealed that the native forms distinguished by ANS probe are two conformational sub‐ensembles. Both sub‐ensembles are active and consist of a series of forms, which pre‐exist in solution and can bind with different substrates. The K m values of N 1 for AMP, ADP and MgATP are larger than that of N 2 , indicating that the N 2 sub‐ensemble is more specific for binding substrates. This is consistent with the previous observation that the activity of N 2 is about 1.8‐fold of that of N 1 .