Histone subunit interactions as investigated by high pressure

Scarlata, Suzanne; Ropp, Traci; Royer, Catherine A.

doi:10.1021/bi00442a016

Cited by 13 publications

(8 citation statements)

References 21 publications

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“…5), which revealed a decrease in the proportion of tetramers and an increase in monomers after pressurization. This is in line with previous studies of pressure effects on a number of tetrameric enzymes that showed dissociation into monomers [36–44]. However, those studies showed reversible tetramer dissociation, whereas we have found that under nonreducing conditions pyruvate kinase was irreversibly dissociated and inactivated by pressure (see below).…”

Section: Discussionsupporting

confidence: 93%

Subunit dissociation and inactivation of pyruvate kinase by hydrostatic pressure

Felice

Soares

Ferreira

1999

European Journal of Biochemistry

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The effect of hydrostatic pressure on the stability of tetrameric rabbit muscle pyruvate kinase was investigated by enzyme activity measurements, size-exclusion chromatography, circular dichroism and fluorescence spectroscopies. Under nonreducing conditions, enzyme activity was irreversibly inhibited by increasing pressure and was completely abolished at 350 MPa. Inhibition was dependent on the concentration of pyruvate kinase, indicating that it was related to pressure-induced subunit dissociation. Size-exclusion chromatography of pressurized samples confirmed a decrease in the proportion of tetramers and an increase in monomers relative to native samples. Addition of dithiothreitol immediately following pressure release led to full recovery of both enzyme activity and of native tetramers. Furthermore, no irreversible inhibition of pyruvate kinase was observed if pressure treatment was carried out in the presence of dithiothreitol. These data suggest that pressure-dissociated monomers undergo conformational changes leading to oxidation of sulfhydryl groups, which prevents correct refolding of native tetramers on decompression. These conformational changes are relatively subtle, as indicated by the lack of significant changes in far-UV circular dichroism and intrinsic fluorescence emission spectra of previously pressurized samples. The effects of various physiological ligands on the pressure stability of pyruvate kinase were also investigated. A slight protection against inhibition was observed in the simultaneous presence of K + , Mg 2+ and ADP. Both phosphoenolpyruvate and the allosteric inhibitor, phenylalanine, caused marked stabilization against pressure, suggesting significant energy coupling between binding of these ligands and stabilization of the tetramer.Keywords: pyruvate kinase; hydrostatic pressure; ligand binding; subunit dissociation; inactivation.Pyruvate kinase is an important regulatory glycolytic enzyme that catalyses the transfer of the phosphoryl group from phosphoenolpyruvate (PEP) to ADP, generating ATP and pyruvate. Pyruvate kinase requires both K and Mg 2 for activity [1±6]. In mammals, four different isozymes of pyruvate kinase that have different kinetic properties exist. The muscle isozyme (M1) is a homotetramer of 59 kDa subunits and does not exhibit cooperative behavior [7]. The kinetic mechanisms of pyruvate kinase from various sources and organisms have been investigated in detail [8±13]. The three-dimensional structure of rabbit muscle pyruvate kinase complexed with K + , Mn 2+ and pyruvate has recently been determined [14].The unfolding and refolding of pyruvate kinase by denaturing agents such as guanidine hydrochloride and urea have been investigated and were shown to be only partially reversible [15±20]. Hydrostatic pressure has been increasingly used to study protein subunit interactions and stability (reviewed in [21±23]). Protein oligomers ranging from dimers to large aggregates such as viral particles have been shown to undergo pressure-induced subunit dissociation. Press...

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Section: Discussionsupporting

confidence: 93%

Subunit dissociation and inactivation of pyruvate kinase by hydrostatic pressure

Felice

Soares

Ferreira

1999

European Journal of Biochemistry

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“…Reported in vitro K d values for chromatin binding proteins span several orders of magnitude 29, 30, 32–45 (Table 1). The Polycomb proteins are an interesting example.…”

Section: How Strong? In Vitro Studies Reveal Very Different Binding Amentioning

confidence: 99%

Epigenetics meets mathematics: Towards a quantitative understanding of chromatin biology

2012

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How fast? How strong? How many? So what? Why do numbers matter in biology? Chromatin binding proteins are forever in motion, exchanging rapidly between bound and free pools. How do regulatory systems whose components are in constant flux ensure stability and flexibility? This review explores the application of quantitative and mathematical approaches to mechanisms of epigenetic regulation. We discuss methods for measuring kinetic parameters and protein quantities in living cells, and explore the insights that have been gained by quantifying and modelling dynamics of chromatin binding proteins.

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“…On the other hand, binding of the operator DNA sequence destabilizes the tetramer considerably. Dissociation constants for histone octamers, tetramers and dimers have been determined by using fluorescence polarization under high pressure (Scarlata et al, 1989).…”

Section: Dna-binding Proteinsmentioning

confidence: 99%

Proteins under pressure

Groß

Jaenicke

1994

European Journal of Biochemistry

661

393

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Oceans not only cover the major part of the earth's surface but also reach into depths exceeding the height of the Mt Everest. They are populated down to the deepest levels (=11800 m), which means that a significant proportion of the global biosphere is exposed to pressures of up to 120 MPa. Although this fact has been known for more than a century, the ecology of the 'abyss' is still in its infancy. Only recently, barophilic adaptation, i.e. the requirement of elevated pressure for viability, has been firmly established. In non-adapted organisms, increased pressure leads to morphological anomalies or growth inhibition, and ultimately to cell death. The detailed molecular mechanism of the underlying 'metabolic dislocation' is unresolved.Effects of pressure as a variable in microbiology, biochemistry and biotechnology allow the structure/function relationship of proteins and protein conjugates to be analyzed. In this context, stabilization by cofactors or accessory proteins has been observed. High-pressure equipment available today allows the comprehensive characterization of the behaviour of proteins under pressure. Single-chain proteins undergo pressure-induced denaturation in the 100-MPa range, which, in the case of oligomeric proteins or protein assemblies, is preceded by dissociation at lower pressure. The effects may be ascribed to the positive reaction volumes connected with the formation of hydrophobic and ionic interactions. In addition, the possibility of conformational effects exerted by moderate, non-denaturing pressures, and related to the intrinsic compressibility of proteins, is discussed. Crystallization may serve as a model reaction of protein self-organization. Kinetic aspects of its pressureinduced inhibition can be described by a model based on the Oosawa theory of molecular association. Barosensitivity is known to be correlated with the pressure-induced inhibition of protein biosynthesis. Attempts to track down the ultimate cause in the dissociation of ribosomes have revealed remarkable stabilization of functional complexes under pseudo-physiological conditions, with the post-translational complex as the most pressure-sensitive species. Apart from the key issue of barosensitivity and barophilic adaptation, high-pressure biochemistry may provide means to develop new approaches to nonthermic industrial processes, especially in the field of food technology.Life in the deep sea faces a whole set of unfavourable conditions, including pressures up to 120 MPa (1200 bar), temperatures around 2°C or, in volcanic regions, above 1OO"C, absence of sunlight, and scarce supply of organic nutrients. When 'deep' means deeper than 1000 m, these biotopes include more than half (~6 2 % ) of the volume of the global biosphere (Jannasch and Taylor, 1984). The average pressure on the ocean floor is of the order of 38 MPa, indicatCorrespondence to R. Jaenicke,

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Histone subunit interactions as investigated by high pressure

Cited by 13 publications

References 21 publications

Subunit dissociation and inactivation of pyruvate kinase by hydrostatic pressure

Subunit dissociation and inactivation of pyruvate kinase by hydrostatic pressure

Epigenetics meets mathematics: Towards a quantitative understanding of chromatin biology

Proteins under pressure

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