Thermostability and activation by divalent cations of the membrane-bound inorganic pyrophosphatase of Rhodospirillum rubrum

Ordaz, Héctor; Sosa, Alejandro Zamudio; Romero, Irma; Célis, Heliodoro

doi:10.1016/0020-711x(92)90181-y

Cited by 3 publications

(2 citation statements)

References 20 publications

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“…3a-c). Activation of the enzyme by metal ions is known to be strongly dependent on metal ion concentration 11,23 and in this study the enzyme responded sensitively to changes in the cation concentration of the reaction mixture. A high concentration of Zn 2+ ions inhibited enzyme activity, similar to the PPase of Rhodospirillum rubrum 24 .…”

Section: Results and Discussion Molecular Propertiesmentioning

confidence: 69%

Functional Characteristics of Inorganic Pyrophosphatase from Psychrotroph Shewanella sp. AS-11 upon Activation by Various Divalent Cations

Ginting¹,

Maeganeku²,

Motoshima³

et al. 2014

Asian J. Chem.

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Inorganic pyrophosphatase (PPase) is an essential enzyme in all living organisms, as it hydrolyzes inorganic pyrophosphate (PPi) to phosphate (Pi). Inorganic pyrophosphatase are only active in the presence of metal ion cofactors. This research investigated effects of various divalent cations on the functional characteristics of psychrotroph Shewanella sp. AS-11 (Sh-PPase). The results showed Co 2+ , Mn 2+ and Zn 2+ markedly activated the enzyme. The optimal temperature for activity of Sh-PPase activated by Mn 2+ was surprisingly low (5 °C), while those of Zn, Co and Mg-activated enzymes were 20, 30 and 40 °C, respectively. The specific activities of Sh-PPases activated by Co 2+ , Mn 2+ and Zn 2+ were 100-, 45-and 12-fold higher than Mg-activated Sh-PPase at 5 ºC, respectively. Sh-PPase activated by Co 2+ or Mn 2+ was stable up to 40 ºC and activated by Zn 2+ up to 50 ºC. Activation of Sh-PPase with Co 2+ , Mn 2+ and Zn 2+ enhanced kcat, but did not significantly affect Km. Thus divalent cations markedly influenced the catalytic efficiency, temperature dependency and thermo-stability of Sh-PPase. Mn 2+ or Co 2+ ions are required to gain cold-adapted characteristics.

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Section: Results and Discussion Molecular Propertiesmentioning

confidence: 69%

Functional Characteristics of Inorganic Pyrophosphatase from Psychrotroph Shewanella sp. AS-11 upon Activation by Various Divalent Cations

Ginting¹,

Maeganeku²,

Motoshima³

et al. 2014

Asian J. Chem.

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“…In the R. rubrum enzyme, free Mg 2+ had an activating effect, while C. sphaeroides had a strong inhibitory effect ( Celis et al, 2003 ). The activation energies of the family I R. rubrum enzyme and family II C. spaheroides enzyme are different; that of the R. rubrum enzyme is 67.3 kJ/mol, while that of the C. sphaeroides enzyme is 36.94 kJ/mol ( Ordaz et al, 1992 ; Celis et al, 2003 ). These results are in agreement with the temperature sensitivity of the C. sphaeroides enzyme.…”

Section: Cytoplasmic Ppases Families and Structural Featuresmentioning

confidence: 96%

The inorganic pyrophosphatases of microorganisms: a structural and functional review

García-Contreras,

de la Mora,

Mora-Montes

et al. 2024

PeerJ

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Pyrophosphatases (PPases) are enzymes that catalyze the hydrolysis of pyrophosphate (PPi), a byproduct of the synthesis and degradation of diverse biomolecules. The accumulation of PPi in the cell can result in cell death. Although the substrate is the same, there are variations in the catalysis and features of these enzymes. Two enzyme forms have been identified in bacteria: cytoplasmic or soluble pyrophosphatases and membrane-bound pyrophosphatases, which play major roles in cell bioenergetics. In eukaryotic cells, cytoplasmic enzymes are the predominant form of PPases (c-PPases), while membrane enzymes (m-PPases) are found only in protists and plants. The study of bacterial cytoplasmic and membrane-bound pyrophosphatases has slowed in recent years. These enzymes are central to cell metabolism and physiology since phospholipid and nucleic acid synthesis release important amounts of PPi that must be removed to allow biosynthesis to continue. In this review, two aims were pursued: first, to provide insight into the structural features of PPases known to date and that are well characterized, and to provide examples of enzymes with novel features. Second, the scientific community should continue studying these enzymes because they have many biotechnological applications. Additionally, in this review, we provide evidence that there are m-PPases present in fungi; to date, no examples have been characterized. Therefore, the diversity of PPase enzymes is still a fruitful field of research. Additionally, we focused on the roles of H+/Na+ pumps and m-PPases in cell bioenergetics. Finally, we provide some examples of the applications of these enzymes in molecular biology and biotechnology, especially in plants. This review is valuable for professionals in the biochemistry field of protein structure–function relationships and experts in other fields, such as chemistry, nanotechnology, and plant sciences.

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Rhodobacter sphaeroides has a family II pyrophosphatase: comparison with other species of photosynthetic bacteria

et al. 2003

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The cytoplasmic pyrophosphatase from Rhodobacter sphaeroides was purified and characterized. The enzyme is a homodimer of 64 kDa. The N-terminus was sequenced and used to obtain the complete pyrophosphatase sequence from the preliminary genome sequence of Rba. sphaeroides, showing extensive sequence similarity to family II or class C pyrophosphatases. The enzyme hydrolyzes only Mg-PP(i) and Mn-PP(i) with a K(m) of 0.35 mM for both substrates. It is not activated by free Mg (2+), in contrast to the cytoplasmic pyrophosphatase from Rhodospirillum rubrum, and it is not inhibited by NaF, methylendiphosphate, or imidodiphosphate. This work shows that Rba. sphaeroides and Rhodobacter capsulatus cytoplasmic pyrophosphatases belong to family II, in contrast to Rsp. rubrum, Rhodopseudomonas palustris, Rhodopseudomonas gelatinosa, and Rhodomicrobium vannielii cytoplasmic pyrophosphatases which should be classified as members of family I. This is the first report of family II cytoplasmic pyrophosphatases in photosynthetic bacteria and in a gram-negative organism.

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Thermostability and activation by divalent cations of the membrane-bound inorganic pyrophosphatase of Rhodospirillum rubrum

Cited by 3 publications

References 20 publications

Functional Characteristics of Inorganic Pyrophosphatase from Psychrotroph Shewanella sp. AS-11 upon Activation by Various Divalent Cations

Functional Characteristics of Inorganic Pyrophosphatase from Psychrotroph Shewanella sp. AS-11 upon Activation by Various Divalent Cations

The inorganic pyrophosphatases of microorganisms: a structural and functional review

Rhodobacter sphaeroides has a family II pyrophosphatase: comparison with other species of photosynthetic bacteria

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