Contributions of hydrogen bonds of Thr 157 to the thermodynamic stability of phage T4 lysozyme

Alber, Tom; Sun, Dao Pin; Wilson, Keith; Wozniak, Joan A.; Cook, Sean P.; Matthews, Brian W.

doi:10.1038/330041a0

Cited by 295 publications

(141 citation statements)

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“…I47 A between the structures (Table 2). This interaction resembles one seen in the structure of a T157G mutant of T4 lysozyme (Alber et al, 1987;Matthews, 1993), where an ordered water molecule, acting as a surrogate for the missing T157 hydroxyl, preserves the pattern of stabilizing hydrogen bonding interactions seen in the native protein. It is interesting that, in spite of the high degree of conservation seen in the structure of the R42I mutant complex, CN inhibition is nonetheless reduced by -180-fold ( Table I).…”

Section: S Itoh and M A Naviamentioning

confidence: 62%

Structure comparison of native and mutant human recombinant FKBP12 complexes with the immunosuppressant drug FK506 (tacrolimus)

Itoh

Navia

1995

Protein Science

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The consequences of site-directed mutagenesis experiments are often anticipated by empirical rules regarding the expected effects of a given amino acid substitution. Here, we examine the effects of "conservative" and "nonconservative" substitutions on the X-ray crystal structures of human recombinant FKBP12 mutants in complex with the immunosuppressant drug FK506 (tacrolimus). R42K and R42I mutant complexes show 1 10-fold and 180-fold decreased calcineurin (CN) inhibition, respectively, versus the native complex, yet retain full peptidyl prolyl isomerase (PPIase) activity, FK506 binding, and FK506-mediated PPIase inhibition. Interestingly, the structure of the R42I mutant complex is better conserved than that of the R42K mutant complex when compared to the native complex structure, within both the FKBP12 protein and FK506 ligand regions of the complexes, and with respect to temperature factors and RMS coordinate differences. This is due to compensatory interactions mediated by two newly ordered water molecules in the R42I complex structure, molecules that act as surrogates for the missing arginine guanidino nitrogens of R42. The absence of such surrogate solvent interactions in the R42K complex leads to some disorder in the so-called "40s loop" that encompasses the substituent. One rationalization proposed for the observed loss in CN inhibition in these R42 mutant complexes invokes indirect effects leading to a misorientation of FKBP12 and FK506 structural elements that normally interact with calcineurin. Our results with the structure of the R42I complex in particular suggest that the observed loss of CN inhibition might also be explained by the loss of a specific R42-mediated interaction with CN that cannot be mimicked effectively by the solvent molecules that otherwise stabilize the conformation of the 40s loop in that structure.

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Section: S Itoh and M A Naviamentioning

confidence: 62%

Structure comparison of native and mutant human recombinant FKBP12 complexes with the immunosuppressant drug FK506 (tacrolimus)

Itoh

Navia

1995

Protein Science

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“…Zhang and Matthews (1994) observed that those most conserved are frequently internal and are characterized by low crystallographic thermal factors. It has been suggested that well-ordered, internal water molecules are significant factors in determining structural stability (Alber et al, 1987;Williams et al, 1994) or function (Alexander et al, 1991;Meyer, 1992). The subject has been reviewed by Westhof (1993) and by Teeter (1991).…”

Section: Conserved Buried Water Molecules In the Lysozyme Corementioning

confidence: 99%

Thermal stability determinants of chicken egg‐white lysozyme core mutants: Hydrophobicity, packing volume, and conserved buried water molecules

1995

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A series of 24 mutants was made in the buried core of chicken lysozyme at positions 40, 5 5 , and 91. The midpoint temperature of thermal denaturation transition (T,) values of these core constructs range from 60.9 to 77.3 "C, extending an earlier, more limited investigation on thermostability. The T,,, values of variants containing conservative replacements for the wild type (WT) (Thr 40-Ile 55-Ser 91) triplet are linearly correlated with hydrophobicity (r = 0.81) and, to a lesser degree, with combined side-chain volume (r = 0.75). The X-ray structures of the S91A (1.9A) and 155L/S91T/DlOlS (1.7 A) mutants are presented. The former amino acid change is found in duck and mammalian lysozymes, and the latter contains the most thermostable core triplet. A network of four conserved, buried water molecules is associated with the core. It is postulated that these water molecules significantly influence the mutational tolerance at the individual triplet positions. The pH dependence of T, for the S91D mutant was compared with that of WT enzyme. The pK, of S91D is 1.2 units higher in the native than in the denatured state, corresponding to AAG298 = 1.7 kcal/mol. This is a low value for charge burial and likely reflects the moderating influence of the buried water molecules or a conformational change. Thermal and chemical denaturation and far UV CD spectroscopy were used to characterize the in vitro properties of I55T. This variant, which buries a hydroxyl group, has similar properties to those of the human amyloidogenic variant I56T.

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“…Studies of T4 lysozyme mutants have suggested that mutations that remove hydrogen-bonding residues are less destabilizing if the replacements are small residues that allow room for a hydrogen-bonding water molecule to be positioned at the site of the mutation (Alber et al, 1987). Therefore, it is interesting to compare the stability of N43G to those of mutations in which Asn 43 is replaced by a bulkier residue.…”

Section: Hydrogen Bondsmentioning

confidence: 99%

Crevice‐forming mutants in the rigid core of bovine pancreatic trypsin inhibitor: Crystal structures of F22A, Y23A, N43G, and F45A

et al. 1993

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Crystal structures of four mutants of bovine pancreatic trypsin inhibitor (F22A, Y23A, N43G, and F45A), engineered to alter their stability properties, have been determined. The mutated residues, which are highly conserved among Kunitz-type inhibitors, are located in the rigid core of the molecule. Replacement of the partially buried bulky residues of the wild-type protein with smaller residues resulted in crevices open to the exterior of the molecule. The overall three-dimensional structure of these mutants is very similar to that of the wild-type protein and only small rearrangements are observed among the atoms lining the crevices.

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Contributions of hydrogen bonds of Thr 157 to the thermodynamic stability of phage T4 lysozyme

Cited by 295 publications

References 0 publications

Structure comparison of native and mutant human recombinant FKBP12 complexes with the immunosuppressant drug FK506 (tacrolimus)

Structure comparison of native and mutant human recombinant FKBP12 complexes with the immunosuppressant drug FK506 (tacrolimus)

Thermal stability determinants of chicken egg‐white lysozyme core mutants: Hydrophobicity, packing volume, and conserved buried water molecules

Crevice‐forming mutants in the rigid core of bovine pancreatic trypsin inhibitor: Crystal structures of F22A, Y23A, N43G, and F45A

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