PsbP is an extrinsic protein of PSII having a function of Ca2+ and Cl- retention in the water-oxidizing center (WOC). In order to understand the mechanism how PsbP regulates the Cl- binding in WOC, we examined the effect of PsbP depletion on the protein structures around the Cl- sites using Fourier transform infrared (FTIR) spectroscopy. Light-induced FTIR difference spectra upon the S1-S2 transition were obtained using Cl--bound and NO3--substituted PSII membranes in the presence and absence of PsbP. A clear difference in the amide I band changes by PsbP depletion was observed between Cl--bound and NO3--substituted PSII samples, indicating that PsbP binding perturbed the protein conformations around the Cl-ion(s) in WOC. It is suggested that PsbP stabilizes the Cl- binding by regulating the dissociation constant of Cl- and/or an energy barrier of Cl- dissociation through protein conformational changes around the Cl- ion(s)., J. Kondo, T. Noguchi., and Obsahuje bibliografické odkazy
The PsbM (3.9 kDa) and PsbY (4.2 kDa) proteins are membrane-spanning, single-helix, subunits associated with the chlorophyll-binding CP47 pre-complex of photosystem II (PSII). Removal of PsbM resulted in accumulation of PSII pre-assembly complexes and impaired electron transfer between the primary (QA) and secondary (QB) plastoquinone electron acceptors of PSII indicating that the QB-binding site and bicarbonate binding to the non-heme iron were altered in this strain. Removal of PsbY alone had only a minor impact on PSII activity but deleting PsbY in the PsbM background led to additional modification of the acceptor side resulting in PsbM:PsbY cells being susceptible to photodamage and this required protein synthesis for recovery. Addition of bicarbonate was able to compensate for the light-induced damage in PsbM:PsbY cells potentially re-occupying the modified bicarbonate-binding site in the PsbM:PsbY strain and complementation of PsbM:PsbY cells with the psbY gene restored the PsbM phenotype., S. Biswas, J. J. Eaton-Rye., and Obsahuje bibliografické odkazy
In this paper, for the impulsive fractional integro-differential equations involving Caputo fractional derivative in Banach space, we investigate the existence and uniqueness of a pseudo almost periodic PC-mild solution. The working tools are based on the fixed point theorems, the fractional powers of operators and fractional calculus. Some known results are improved and generalized. Finally, existence and uniqueness of a pseudo almost periodic PC-mild solution of a two-dimensional impulsive fractional predator-prey system with diffusion are investigated., Zhinan Xia., and Obsahuje bibliografii
A new nematode species, Pseudocapillaria indica sp. п., is described from the intestine of the freshwater fish Channa gachua (Hamilton) from Kerala, India. It resembles P. tomentosa (Dujardin, 1843), differing from it mainly in the structure of the proximal end of spicule, the shape and structure of the stichocytes and in having smaller eggs (size 0.036-0.048 x 0.023-0.027 mm) which have a different type of superficial structure. Pseudocapillaria indica is the first capillariid species described from freshwater fishes of India and from the whole Oriental Region.
A new nematode species, Pseudocapillaria yucatanensis sp. n., is described from the intestine of the freshwater pimelodid catfish Rhamdia guatemalensis (Günther) from cenotes (= sinkholes) in Yucatan, Mexico. It differs from other three related species parasitizing freshwater fishes mainly in possessing the spicule with a simple rim of its proximal end and a non-expanded distal end, in the length of the spicule (0.218-0.295 mm), and the size (0.050-0.060 x 0.025-0.030 mm), shape and structure of eggs, and also in the host types and geographical distribution. Pseudocapillaria yucatanensis is the first known autochtonous species of Pseudocapillaria parasitizing freshwater fishes in Mexico.