Hydrophobic bonding and conformational transitions in lysozyme, ribonuclease and chymotrypsin

Foss, John G.

doi:10.1016/0006-3002(61)90552-2

Cited by 62 publications

(12 citation statements)

References 17 publications

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“…The *® for the main transition of about -2000 (Figure 2) for the normalization of two tyrosyl residues is slightly higher than that previously reported by Hermans and Scheraga (1961), Foss (1961), andScott and. This could be due to the low ionic strengths and/or pH employed in these studies since a change from acid to neutral pH conditions causes an apparent decrease in -At^.…”

Section: Resultscontrasting

confidence: 56%

“…The concentrations of the deionized ribonuclease 1 The reversible thermal transition of ribonuclease has been examined by numerous investigators (Harrington and Schellman, 1956;Kalnitsky and Resnick, 1959;Foss and Schellman, 1959;Hermans and Scheraga, 1961;Foss, 1961; Holcomb and Van Holde, 1962; Scott and Scheraga, 1963). The specific optical rotation, the specific activity, the absorption spectrum, the intrinsic viscosity, and the sedimentation rate of ribonuclease have been used as indicators of the configurational changes in the molecule produced by heat.…”

Section: Methodsmentioning

confidence: 99%

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Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease^*

Ginsburg¹,

Carroll²

1965

Biochemistry

135

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Section: Resultscontrasting

confidence: 56%

Section: Methodsmentioning

confidence: 99%

Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease^*

Ginsburg¹,

Carroll²

1965

Biochemistry

135

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“…A shift in the absorption of the aromatic amino acids is also induced simply by heat, and small thermal difference spectra, necessarily of much the same shape, are observed when a solution of the chroniophoric amino acid or its derivative at high temperature is measured against a solution at room temperature. Several such spectra have been described by Foss [17]. When a protein is thermally denatured this purely thermal effect is superimposed on the much larger dcnaturation difference spectrum [18,19].…”

Section: Fig 2 Solvent-induced Conformational Transition Of Glucagonmentioning

confidence: 99%

A Conformational Study of Glucagon

Gratzer

Beven

Rrattle

et al. 1968

European Journal of Biochemistry

106

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Glucagon is a polypeptide of 29 residues, which can be crystallised. Optical rotatory dispersion in dilute neutral, acid and alkaline solution suggests that the polypeptide chain is largely random, but contains about one turn of a-helix, which is eliminated in 6 M guanidine hydrochloride.Using thermal difference spectra, nuclear magnetic resonance, and the temperature-dependence of the optical rotatory dispersion as criteria, it appears that glucagon possesses no defined tertiary structure in solution, but may be regarded as bcing in a state ofa-helix s random coil equilibrium, near the high-temperature end of the transition range. That there is no steric objection to the formation of a highly a-helical conformation is demonstrated by optical rotatory dispersion measurements in 2-chloroethanoi solution, in which the protein becomes largely helical. A rough calculation indicates that in aqueous solution a t pH 2 the transition mid-point is at about -40". From changes in the proton magnetic resonance spectrum when glucagon is transferred from an aqueous environment into 6 M guanidine hydrochloride, it is deduced that the short helical segment in the chain in the aqueous state contains most of the long aliphatic side chains, and since the sequence is known it has been possible to identify such a segment uniquely near the C-terminal end. On standing in acid solution the viscosity increases and a birefringent gel is formed. Sedimentation studies indicate the formation of large aggregates. On further standing, or warming, a precipitate appears which has the appearance of long fibrils in the electron microscope. Infrared spectra of the gel, of solid films and of the precipitated material show that in all these states the glucagon is in the form of antiparallel P-chains.Glucagon is a peptide hormone of molecular weight 3,500, with a known sequence [I]. It has been reported [21 that glucagon crystals are cubic, and it was suggested that the molecule in the crystal is cylindrical, and t,herefore in the a-helical form. The only molecules of comparable length which are known to exist in the fully helical state are homopolypeptides, and a considerable body of evidence has built up [3,4] which indicates that the helical segments in globular proteins depend for their conformational stability on hydrophobic contacts in the interior of the protein. Moreover no proteins in the size range of glucagon have so far been found to have rigid tertiary structures. It is of interest t o investigate the secondary structure of glucagon under various conditions, in order to determine the nature of the secondary structure, and whether a tertiary structure can be said to exist. A brief account of part of the work on the aggregated states has appeared [5]. EXPERIMENTAL PROCEDURE MaterialsThe glucagon samples used in this study were given by Dr. J. Schlichtkrull (Novo Research Institute) and Mr. T. Couling (Lilly Research Laboratories Ltd.). This crystalline material was homogeneous by paper electrophoresis a t several pH values. I n starch gel ...

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“…The denaturation of wild-type enzyme has been studied extensively (e.g., Foss, 1961;Pfeil& Privalov, 1976a, 1976b, 1976cRadford et al, 1992), and the accumulated results provide a substantive platform for the interpretation of newer data obtained with recombinant enzymes. In all modern game bird lysozymes, a triplet of structurally adjacent residues comprising either Thr 40, Ile 5 5 , Ser 91 (TIS), or Ser 40, Val 5 5 , Thr 91 (SVT), is found in an internal core just below the active site (Jolles & Jolles, 1984).…”

mentioning

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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Hydrophobic bonding and conformational transitions in lysozyme, ribonuclease and chymotrypsin

Cited by 62 publications

References 17 publications

Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease^*

Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease^*

A Conformational Study of Glucagon

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

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Hydrophobic bonding and conformational transitions in lysozyme, ribonuclease and chymotrypsin

Cited by 62 publications

References 17 publications

Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease*

Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease*

A Conformational Study of Glucagon

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

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Product

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Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease^*

Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease^*