An enzymatic molten globule: efficient coupling of folding and catalysis.

A highly active, monomeric chorismate mutase, obtained by topological redesign of a dimeric helical bundle enzyme from Methanococcus jannaschii, was investigated by NMR and various other biochemical techniques, including H/D exchange. Although structural disorder is generally considered to be incompatible with efficient catalysis, the monomer, unlike its natural counterpart, unexpectedly possesses all of the characteristics of a molten globule. Global conformational ordering, observed upon binding of a transition state analog, indicates that folding can be coupled to catalysis with minimal energetic penalty. These results support the suggestion that many modern enzymes might have evolved from molten globule precursors. Insofar as their structural plasticity confers relaxed substrate specificity and/or catalytic promiscuity, molten globules may also be attractive starting points for the evolution of new catalysts in the laboratory.

[1]  Charles R. Johnson,et al.  An inhibitor of chorismate mutase resembling the transition-state conformation , 1985 .

[2]  Yinan Wei,et al.  Solution structure of a de novo protein from a designed combinatorial library , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[3]  K. Kuwajima,et al.  The molten globule state as a clue for understanding the folding and cooperativity of globular‐protein structure , 1989, Proteins.

[4]  L. Iakoucheva,et al.  Intrinsic Disorder and Protein Function , 2002 .

[5]  R. Sauer,et al.  Sequence space, folding and protein design. , 1996, Current opinion in structural biology.

[6]  Donald Hilvert,et al.  Investigating and Engineering Enzymes by Genetic Selection. , 2001, Angewandte Chemie.

[7]  P. Karplus,et al.  ATOMIC-STRUCTURE OF THE BURIED CATALYTIC POCKET OF ESCHERICHIA-COLI CHORISMATE MUTASE. , 1995 .

[8]  D. Hilvert,et al.  Redesigning enzyme topology by directed evolution. , 1998, Science.

[9]  Dan S. Tawfik,et al.  Conformational diversity and protein evolution--a 60-year-old hypothesis revisited. , 2003, Trends in biochemical sciences.

[10]  A. Wada,et al.  ‘Molten‐globule state’: a compact form of globular proteins with mobile side‐chains , 1983, FEBS letters.

[11]  O. Ptitsyn,et al.  α‐lactalbumin: compact state with fluctuating tertiary structure? , 1981, FEBS letters.

[12]  N. A. Rodionova,et al.  Study of the “molten globule” intermediate state in protein folding by a hydrophobic fluorescent probe , 1991, Biopolymers.

[13]  G. Fasman.  Circular Dichroism and the Conformational Analysis of Biomolecules , 1996, Springer US.

[14]  Min Zhou,et al.  Ligand binding energy and catalytic efficiency from improved packing within receptors and enzymes. , 2003, Journal of molecular biology.

[15]  Zhongqi Zhang,et al.  Probing the non-covalent structure of proteins by amide hydrogen exchange and mass spectrometry. , 1997, Journal of mass spectrometry : JMS.

[16]  D. Koshland.  The Key–Lock Theory and the Induced Fit Theory , 1995 .

[17]  D. Hilvert,et al.  A small, thermostable, and monofunctional chorismate mutase from the archaeon Methanococcus jannaschii. , 1998, Biochemistry.

[18]  W. DeGrado,et al.  Protein Design: A Hierarchic Approach , 1995, Science.

[19]  Y. Li,et al.  Double point mutant F34W/W140F of staphylococcal nuclease is in a molten globule state but highly competent to fold into a functional conformation. , 2000, Journal of biochemistry.

[20]  C. Dobson.  Protein misfolding, evolution and disease. , 1999, Trends in biochemical sciences.

[21]  W. DeGrado.  Catalytic molten globules , 1993, Nature.

[22]  H. Dyson,et al.  Coupling of folding and binding for unstructured proteins. , 2002, Current opinion in structural biology.

[23]  O. Ptitsyn,et al.  Evidence for a molten globule state as a general intermediate in protein folding , 1990, FEBS letters.

[24]  T. Sosnick,et al.  Hydrogen exchange: The modern legacy of Linderstrøm‐Lang , 1997, Protein science : a publication of the Protein Society.

[25]  Dan S. Tawfik,et al.  Antibody Multispecificity Mediated by Conformational Diversity , 2003, Science.

[26]  G. Hammes.  Multiple conformational changes in enzyme catalysis. , 2002, Biochemistry.

[27]  V. Uversky,et al.  Circularly permuted dihydrofolate reductase possesses all the properties of the molten globule state, but can resume functional tertiary structure by interaction with its ligands , 1996, Protein science : a publication of the Protein Society.

[28]  D. Raleigh,et al.  Defining the core structure of the alpha-lactalbumin molten globule state. , 1999, Journal of molecular biology.

[29]  C. Tsou.  Inactivation precedes overall molecular conformation changes during enzyme denaturation. , 1995, Biochimica et biophysica acta.