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The stability and hydrophobicity of cytosolic and mitochondrial malate dehydrogenases and their relation to chaperonin‐assisted folding
Author(s) -
Staniforth Rosemary A.,
Cortés Antonio,
Burston Steven G.,
Atkinson Tony,
Holbrook J.John,
Clarke Anthony R.
Publication year - 1994
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 - 10.1016/0014-5793(94)00348-3
Subject(s) - chaperonin , chemistry , biochemistry , protein folding , malate dehydrogenase , cytosol , folding (dsp implementation) , yield (engineering) , enzyme , biophysics , biology , thermodynamics , electrical engineering , engineering , physics
mMDH and cMDH are structurally homologous enzymes which show very different responses to chaperonins during folding. The hydrophilic and stable cMDH is bound by cpn60 but released by MG‐ATP alone, while the hydrophobic and unstable mMDH requires both Mg‐ATP and cpn 10. Citrate equalises the stability of the native state of the two proteins but has no effect on the co‐chaperonin requirement, implying that hydrophobicity, and not stability, is the determining factor. The yield and rate of folding of cMDH is unaffected while that of mMDH is markedly increased by the presence of cpn60, cpn10 and Mg‐ATP. In 200 mM orthophosphate, chaperonins do not enhance the rate of folding of mMDH, but in low phosphate concentrations chaperonin‐assisted folding is 3–4‐times faster.