Laser Flash-Induced Kinetic Analysis of CytochromefOxidation by Wild-Type and Mutant Plastocyanin from the CyanobacteriumNostocsp. PCC 7119†

Biochemistry ◽  
2005 ◽  
Vol 44 (34) ◽  
pp. 11601-11607 ◽  
Author(s):  
Cristina Albarrán ◽  
José A. Navarro ◽  
Fernando P. Molina-Heredia ◽  
Piedad del S. Murdoch ◽  
Miguel A. De la Rosa ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Laser Flash ◽  
Wild Type

The JH2 domain and SH2-JH2 linker regulate JAK2 activity: A detailed kinetic analysis of wild type and V617F mutant kinase domains

2014 ◽  
Vol 1844 (10) ◽  
pp. 1835-1841 ◽  
Author(s):  
Arturo Sanz Sanz ◽  
Yashavanthi Niranjan ◽  
Henrik Hammarén ◽  
Daniela Ungureanu ◽  
Rob Ruijtenbeek ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Wild Type ◽  
Mutant Kinase

Laser flash kinetic analysis of Synechocystis PCC 6803 cytochrome c6 and plastocyanin oxidation by Photosystem I

1994 ◽  
Vol 1184 (2-3) ◽  
pp. 235-241 ◽  
Author(s):  
Manuel Hervás ◽  
JoséM. Ortega ◽  
JoséA. Navarro ◽  
Miguel A. De la Rosa ◽  
Hervé Bottin
Keyword(s):  
Kinetic Analysis ◽  
Photosystem I ◽  
Laser Flash ◽  
Synechocystis Pcc 6803 ◽  
Cytochrome C6 ◽  
Pcc 6803

Mutagenesis-induced conformational change in domain B of a pullulan-hydrolyzing α-amylase TVA I

Amylase ◽  
2018 ◽  
Vol 2 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Takashi Tonozuka ◽  
Takanori Nihira ◽  
Masahiro Mizuno ◽  
Atsushi Nishikawa ◽  
Shigehiro Kamitori
Keyword(s):  
Kinetic Analysis ◽  
Crystal Structures ◽  
Conformational Change ◽  
The Other ◽  
Wild Type ◽  
Other Hand ◽  
Thermoactinomyces Vulgaris ◽  
Catalytic Cleft

Abstract An α-amylase from Thermoactinomyces vulgaris, TVA I, hydrolyzes both α-1,4- and α-1,6-glucosidic linkages. Two variants of TVA I have been previously constructed, one containing a substitution of three residues, Ala357- Gln359-Tyr360, with Val-Asn-Glu (AQY/VNE), and the other bearing a deletion of 11 residues from Ala363 to Asn373 (Del11). The activities of both AQY/VNE and Del11 for the α-1,4-glucosidic linkage of maltotriose were decreased compared to that of wild-type TVA I, while the activities of the two variants for the α-1,6-glucosidic linkage of a trisaccharide, isopanose, were less significantly altered. Here, we determined the crystal structures of AQY/VNE and Del11. The structure of AQY/VNE was almost isomorphous with that of wild-type TVA I. On the other hand, the structure of Del11 showed that a conformational change in domain B was induced by the 11-residue deletion, causing narrowing of the catalytic cleft. Taken together with the results of kinetic analysis, this narrower catalytic cleft is likely responsible for the preference of the TVA I enzyme for the α-1,6-glucosidic linkage.

A Laser Flash-Induced Kinetic Analysis of in Vivo Photosystem I Reduction by Site-Directed Mutants of Plastocyanin and Cytochromec6inSynechocystissp. PCC 6803†

Biochemistry ◽  
2006 ◽  
Vol 45 (3) ◽  
pp. 1054-1060 ◽  
Author(s):  
Raúl V. Durán ◽  
Manuel Hervás ◽  
Berta De la Cerda ◽  
Miguel A. De la Rosa ◽  
José A. Navarro
Keyword(s):  
Kinetic Analysis ◽  
Photosystem I ◽  
Laser Flash ◽  
Pcc 6803

scholarly journals A Pre-Steady State Kinetic Analysis of the αY60W Mutant oftrans-3-Chloroacrylic Acid Dehalogenase: Implications for the Mechanism of the Wild-Type Enzyme

Biochemistry ◽  
2012 ◽  
Vol 51 (46) ◽  
pp. 9420-9435 ◽  
Author(s):  
Jamison P. Huddleston ◽  
Gottfried K. Schroeder ◽  
Kenneth A. Johnson ◽  
Christian P. Whitman
Keyword(s):  
Steady State ◽  
Kinetic Analysis ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
Steady State Kinetic ◽  
Chloroacrylic Acid Dehalogenase ◽  
State Kinetic

scholarly journals Huge enhanced activity of the alditol oxidase by a novel method based on the mechanically interlocked dimmer synthesized in vivo

2021 ◽  
Author(s):  
Wencai Zhang ◽  
Mianxing Luo ◽  
Meng Zhang ◽  
Guo Chen ◽  
Hongwei Guo ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Kinetic Analysis ◽  
Catalytic Efficiency ◽  
Dramatic Improvement ◽  
Mechanical Interlocking ◽  
Wild Type ◽  
Protein Properties ◽  
Novel Method ◽  
Activity Enhancement

Topology engineering is an attractive approach for tailoring protein properties without varying their native sequences. To explore whether concatenation allow, Herein, we report a dramatic improvement of catalytic efficiencies of alditol oxidase by catenanes assisted by synergy between mechanically interlocking p53dim and highly efficient SpyTag/SpyCathcher cyclization. Mechanical interlocking leads to considerable activity enhancement than that achieved by point mutation. Kinetic analysis demonstrates that the substrates affinity and catalytic efficiency of alditol oxdiase catenanes(catAldO) towards glycerol respectively have 6.7-fold and 5.5-fold improvement compared with the wild-type AldO. We envisioned that mechanically interlocked alditol oxidase may shorten the transfer distance of electrons between subdormains and accelerate FAD cofactor redox regeneration, thus improving enzyme catalytic activity. Surprisingly, concatenation of alditol oxidase not only increase the catalytic efficiency towards glycerol, but also exhibit a broad biocatalytic reinforcement. Mechanical interlocking provides a convenient and efficient approach for multi-domains enzyme concatenation, with potential to greatly enhance the catalytic efficiency of biocatalysts. It needs more verification in other enzymes.

scholarly journals Global spectral–kinetic analysis of room temperature chlorophyll a fluorescence from light-harvesting antenna mutants of barley

2000 ◽  
Vol 355 (1402) ◽  
pp. 1371-1384 ◽  
Author(s):  
Adam M. Gilmore ◽  
Shigeru Itoh ◽  
Govindjee
Keyword(s):  
Energy Transfer ◽  
Energy Dissipation ◽  
Kinetic Analysis ◽  
Room Temperature ◽  
Kinetic Properties ◽  
Wild Type ◽  
Spectral Emission ◽  
Ps Ii ◽  
Main Band ◽  
Ps I

This study presents a novel measurement, and simulation, of the time–resolved room temperature chlorophyll a fluorescence emission spectra from leaves of the barley wild–type and chlorophyll– b –deficient chlorina ( clo ) f2 and f104 mutants. The primary data were collected with a streak–camera–based picosecond–pulsed fluorometer that simultaneously records the spectral distribution and time dependence of the fluorescence decay. A new global spectral–kinetic analysis programme method, termed the double convolution integral (DCI) method, was developed to convolve the exciting laser pulse shape with a multimodal–distributed decay profile function that is again convolved with the spectral emission band amplitude functions. We report several key results obtained by the simultaneous spectral–kinetic acquisition and DCI methods. First, under conditions of dark–level fluorescence, when photosystem II (PS II) photochemistry is at a maximum at room temperature, both the clo f2 and clo f104 mutants exhibit very similar PS II spectral–decay contours as the wild–type ( wt ), with the main band centred around 685 nm. Second, dark–level fluorescence is strongly influenced beyond 700 nm by broad emission bands from PS I, and its associated antennae proteins, which exhibit much more rapid decay kinetics and strong integrated amplitudes. In particular a 705–720 nm band is present in all three samples, with a 710nm band predominating in the clo f2 leaves. When the PS II photochemistry becomes inhibited, maximizing the fluorescence yield, both the clo f104 mutant and the wt exhibit lifetime increases for their major distribution modes from the minimal 250–500 ps range to the maximal 1500–2500 ps range for both the 685 nm and 740 nm bands. The clo f2 mutant, however, exhibits several unique spectral–kinetic properties, attributed to its unique PS I antennae and thylakoid structure, indicating changes in both PS II fluorescence reabsorption and PS II to PS I energy transfer pathways compared to the wt and clo f104 . Photoprotective energy dissipation mediated by the xanthophyll cycle pigments and the PsbS protein was uninhibited in the clo f104 mutant but, as commonly reported in the literature, significantly inhibited in the clo f2 ; the inhibited energy dissipation is partly attributed to its thylakoid structure and PS II to PS I energy transfer properties. It is concluded that it is imperative with steady–state fluorometers, especially for in vivo studies of PS II efficiency or photoprotective energy dissipation, to quantify the influence of the PS I spectral emission.

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