The Experts below are selected from a list of 27 Experts worldwide ranked by ideXlab platform
Satoshi Kanoh - One of the best experts on this subject based on the ideXlab platform.
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effects of urea and trimethylamine n oxide on atpase of Requiem Shark myofibril and its constituents
Fisheries Science, 2001Co-Authors: Satoshi Kanoh, Masaya Kitamura, Yuta Horie, Yuuki Kasama, Eiji NiwaAbstract:: The effects of trimethylamine-N-oxide (TMAO) on the urea-resistibility of Requiem Shark myofibrils were investigated, using Ca2+- and Mg2+-ATPase activities as a parameter. Both activities were hardly changed or activated up to 0.6 M urea. In contrast, the two activities both decreased to less than 50% in the presence of TMAO up to 0.5 M. When measured at a 2 : 1 molar ratio of urea and TMAO, Ca2+- and Mg2+-ATPase activities were similar to those in the presence of TMAO alone, indicating that TMAO reduced the urea-resistibility of myofibrils. Myosin, the most abundant protein in myofibrils, from Requiem Shark exhibited the effects of urea and TMAO on its Ca2+-ATPase activity, which was primarily similar to those of myofibrils. However, Ca2+-ATPase activities in the coexistence of urea and TMAO for actomyosin reconstituted from Requiem Shark myosin and chicken F-actin were approximately average of those measured independently in the presence of either urea or TMAO alone. Carp myofibrils, reconstituted actomyosin and myosin, which were used as teleost references, all showed a tendency in the effects of urea and TMAO on Ca2+-ATPase activities that was similar to those of Requiem Shark counterparts.
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Effects of urea on actin-activated Mg2+-ATPase of Requiem Shark myosin
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1999Co-Authors: Satoshi Kanoh, Eiji Niwa, Yoshiki Osaka, Shugo WatabeAbstract:Abstract The influence of urea on actin-activated myosin Mg 2+ -ATPase of Requiem Shark Triakis scyllia was examined and compared to that of carp ( Cyprinus carpio ). No changes in the maximum turnover rate, V max , was observed for Shark myosin up to 0.3 M urea which is an approximate physiological concentration in marine elasmobranch tissues. The rate for carp myosin decreased by 70% at this urea concentration. The affinity of myosin to actin also remained unchanged up to about 0.7 M urea for Shark in marked contrast to carp myosin which decreased by 30%, even in 0.1 M urea. Since it has been reported that urea-resistibility of Requiem Shark myosin Ca 2+ -ATPase in the absence of actin is comparable to that of carp, a high resistibility against urea in actin-activated Mg 2+ -ATPase of Shark myosin is partly accounted for by its stable interaction with actin.
Eiji Niwa - One of the best experts on this subject based on the ideXlab platform.
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effects of urea and trimethylamine n oxide on atpase of Requiem Shark myofibril and its constituents
Fisheries Science, 2001Co-Authors: Satoshi Kanoh, Masaya Kitamura, Yuta Horie, Yuuki Kasama, Eiji NiwaAbstract:: The effects of trimethylamine-N-oxide (TMAO) on the urea-resistibility of Requiem Shark myofibrils were investigated, using Ca2+- and Mg2+-ATPase activities as a parameter. Both activities were hardly changed or activated up to 0.6 M urea. In contrast, the two activities both decreased to less than 50% in the presence of TMAO up to 0.5 M. When measured at a 2 : 1 molar ratio of urea and TMAO, Ca2+- and Mg2+-ATPase activities were similar to those in the presence of TMAO alone, indicating that TMAO reduced the urea-resistibility of myofibrils. Myosin, the most abundant protein in myofibrils, from Requiem Shark exhibited the effects of urea and TMAO on its Ca2+-ATPase activity, which was primarily similar to those of myofibrils. However, Ca2+-ATPase activities in the coexistence of urea and TMAO for actomyosin reconstituted from Requiem Shark myosin and chicken F-actin were approximately average of those measured independently in the presence of either urea or TMAO alone. Carp myofibrils, reconstituted actomyosin and myosin, which were used as teleost references, all showed a tendency in the effects of urea and TMAO on Ca2+-ATPase activities that was similar to those of Requiem Shark counterparts.
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Effects of urea on actin-activated Mg2+-ATPase of Requiem Shark myosin
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1999Co-Authors: Satoshi Kanoh, Eiji Niwa, Yoshiki Osaka, Shugo WatabeAbstract:Abstract The influence of urea on actin-activated myosin Mg 2+ -ATPase of Requiem Shark Triakis scyllia was examined and compared to that of carp ( Cyprinus carpio ). No changes in the maximum turnover rate, V max , was observed for Shark myosin up to 0.3 M urea which is an approximate physiological concentration in marine elasmobranch tissues. The rate for carp myosin decreased by 70% at this urea concentration. The affinity of myosin to actin also remained unchanged up to about 0.7 M urea for Shark in marked contrast to carp myosin which decreased by 30%, even in 0.1 M urea. Since it has been reported that urea-resistibility of Requiem Shark myosin Ca 2+ -ATPase in the absence of actin is comparable to that of carp, a high resistibility against urea in actin-activated Mg 2+ -ATPase of Shark myosin is partly accounted for by its stable interaction with actin.
Dharmadi Dharmadi - One of the best experts on this subject based on the ideXlab platform.
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KOMPOSISI DAN FLUKTUASI HASIL TANGKAPAN IKAN CUCUT DOMINAN YANG TERTANGKAP RAWAI TUNA PERMUKAAN
'Agency for Marine and Fisheries Research and Development', 2017Co-Authors: Dharmadi Dharmadi, Suprapto Suprapto, Widodo, Agustinus AnungAbstract:Perikanan rawai tuna memiliki kontribusi cukup besar terhadap hasil tangkapan ikan cucut (Requiem Shark sp.) di perairan Samudera Hindia. Hasil tangkapan rawai tuna sebagian besar didaratkan di 2 pendaratan ikan utama yaitu Pelabuhan Perikanan Pelabuhan Ratu dan Pelabuhan Perikanan Samudera Cilacap. Kegiatan penelitian untuk mengetahui komposisi dan fluktuasi hasil tangkapan ikan cucut (Requiem Shark sp.) dominan pada rawai tuna permukaan berbasis di 2 lokasi pendaratan ikan tersebut dilakukan pada tahun 2004. Hasil penelitian menunjukkan bahwa komposisi hasil tangkapan cucut (Requiem Shark sp.) pada rawai tuna permukaan didominansi oleh jenis ikan cucut karet atau selendang (Prionace glauca) antara 40 sampai dengan 90%, sedangkan komposisi jenis ikan cucut lain seperti ikan cucut lanjaman (Carcharhinus falciformis dan Carcharhinus sorrah), cucut paitan (Alopias superciliosus), cucut tikusan (Alopias pelagicus), dan cucut mako (Isurus sp.) antara 3 sampai dengan 30%. Hasil tangkapan ikan cucut (Requiem Shark sp.) terhadap hasil tangkapan total rawai tuna permukaan antara 5 sampai dengan 25% pada tahun 2004 dari rata-rata 85 unit kapal rawai tuna yang beroperasi di perairan Samudera Hindia. Hasil tangkapan ikan cucut (Requiem Shark sp.) tertinggi terjadi pada bulan Juli sampai dengan Agustus. Hasil tangkapan ini berkaitan dengan kondisi cuaca (Requiem Shark sp.) pada saat nelayan melakukan penangkapan ikan di laut. Tuna long lines fisheries have more contributed on the catch of Shark (Requiem Shark sp.) in the Indian Ocean. Most of catch from tuna long lines landed at two main landing sites of tuna long line which operated in the Indian Ocean were Pelabuhan Ratu and Cilacap. This study was conducted at that two landing sites during 2004. The result showed that Shark (RequiemShark sp.) catch composition on tuna long line was dominated by blue Shark, Prionace glauca (40 to 90%), while other Sharks i.e. silky Shark (Carcharhinus falciformis), spot tail Shark (Carcharhinus sorrah), big eye thresher (Alopias superciliosus), pelagic thresher (Alopias pelagicus), and mako Shark (Isurus sp.) between 3 to 30% from the total catch of Shark (Requiem Shark sp.). Percentage catch of Sharks (Requiem Shark sp.) againts total catch of tuna surface long line during 2004 was ranging 5 to 25% from everage of 85 unit of tuna long line boat that operated in the Indian Ocean. Catch fluctuation related with the weather conditon when the fishers are fishing activity at sea. The high catch of Shark (Requiem Shark sp.) was occur on July until August
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HASIL TANGKAPAN CUCUT YANG TERTANGKAP DENGAN JARING INSANG TUNA PERMUKAAN DI PERAIRAN SAMUDERA HINDIA
'Agency for Marine and Fisheries Research and Development', 2017Co-Authors: Dharmadi Dharmadi, Triharyuni Setya, Rianto JokoAbstract:Penelitian ini dilakukan di lokasi pendaratan ikan utama Pelabuhan Perikanan Samudera Cilacap selama tahun 2006-2008. Tujuan penelitian ini untuk mengetahui fluktuasi catch per unit of effort, komposisi, dan fluktuasi hasil tangkapan cucut yang tertangkap dengan jaring insang tuna permukaan. Metode penelitian dengan pengamatan langsung di lapangan dan pengumpulan data hasil tangkapan oleh enumerator. Data hasil tangkapan cucut (Requiem Shark sp.) diperoleh berdasarkan atas catatan harian dari sejumlah kapal yang menggunakan jaring insang tuna permukaan yang beroperasi di perairan Samudera Hindia selama tahun 2007 dan 2008 masing-masing 821 dan 791 unit. Hasil penelitian ini menunjukan telah terjadi indikasi penurunan catch per unit of effort cucut secara bulanan. Nilai catch per unit of effort tahun 2008 mulai menurun setelah bulan Juli sampai Desember, jika dibandingkan tahun 2007 pada periode yang sama (p<0,05). Komposisi hasil tangkapan cucut bervariasi secara bulanan berdasarkan atas spesies yang didominansi oleh Alopias pelagicus (59,4%) dan Alopias superciliosus (21,1%). Fluktuasi hasil tangkapan dari delapan spesies cucut menunjukan variasi yang hampir sama dan puncak hasil tangkapan terjadi pada bulan Juni dan Juli. This study has been conducted at major fish landing sites, Ocean Fishing Port of Cilacap during the period of 2006-2008. The aim of this research is to find out catch per unit of effort fluctuations, composition, and fluctuations of Shark catches are caught by surface tuna gillnet. Research methods with direct observation and catch data collection by enumerator. Shark catch data obtained from daily records from 821 units in 2007 and 791 units in 2008 of the vessels surface tuna gillnet operating in the Indian Ocean. The results show there have been indications of a decrease Shark catch per unit of effort based on a monthly (P<0,05). Catch per unit of effort values in 2008 began to decline after the month of July until December, when compared to the year 2007 in the same period. The composition of Shark catches was vary monthly based on species that are dominated by Alopias pelagicus (59.4%), and Alopias superciliosus (21.1%). Catch fluctuation of the eight species of Shark showed similar variations and peak catches occurred in June and July
Shugo Watabe - One of the best experts on this subject based on the ideXlab platform.
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Effects of urea on actin-activated Mg2+-ATPase of Requiem Shark myosin
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1999Co-Authors: Satoshi Kanoh, Eiji Niwa, Yoshiki Osaka, Shugo WatabeAbstract:Abstract The influence of urea on actin-activated myosin Mg 2+ -ATPase of Requiem Shark Triakis scyllia was examined and compared to that of carp ( Cyprinus carpio ). No changes in the maximum turnover rate, V max , was observed for Shark myosin up to 0.3 M urea which is an approximate physiological concentration in marine elasmobranch tissues. The rate for carp myosin decreased by 70% at this urea concentration. The affinity of myosin to actin also remained unchanged up to about 0.7 M urea for Shark in marked contrast to carp myosin which decreased by 30%, even in 0.1 M urea. Since it has been reported that urea-resistibility of Requiem Shark myosin Ca 2+ -ATPase in the absence of actin is comparable to that of carp, a high resistibility against urea in actin-activated Mg 2+ -ATPase of Shark myosin is partly accounted for by its stable interaction with actin.
Widodo, Agustinus Anung - One of the best experts on this subject based on the ideXlab platform.
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KOMPOSISI DAN FLUKTUASI HASIL TANGKAPAN IKAN CUCUT DOMINAN YANG TERTANGKAP RAWAI TUNA PERMUKAAN
'Agency for Marine and Fisheries Research and Development', 2017Co-Authors: Dharmadi Dharmadi, Suprapto Suprapto, Widodo, Agustinus AnungAbstract:Perikanan rawai tuna memiliki kontribusi cukup besar terhadap hasil tangkapan ikan cucut (Requiem Shark sp.) di perairan Samudera Hindia. Hasil tangkapan rawai tuna sebagian besar didaratkan di 2 pendaratan ikan utama yaitu Pelabuhan Perikanan Pelabuhan Ratu dan Pelabuhan Perikanan Samudera Cilacap. Kegiatan penelitian untuk mengetahui komposisi dan fluktuasi hasil tangkapan ikan cucut (Requiem Shark sp.) dominan pada rawai tuna permukaan berbasis di 2 lokasi pendaratan ikan tersebut dilakukan pada tahun 2004. Hasil penelitian menunjukkan bahwa komposisi hasil tangkapan cucut (Requiem Shark sp.) pada rawai tuna permukaan didominansi oleh jenis ikan cucut karet atau selendang (Prionace glauca) antara 40 sampai dengan 90%, sedangkan komposisi jenis ikan cucut lain seperti ikan cucut lanjaman (Carcharhinus falciformis dan Carcharhinus sorrah), cucut paitan (Alopias superciliosus), cucut tikusan (Alopias pelagicus), dan cucut mako (Isurus sp.) antara 3 sampai dengan 30%. Hasil tangkapan ikan cucut (Requiem Shark sp.) terhadap hasil tangkapan total rawai tuna permukaan antara 5 sampai dengan 25% pada tahun 2004 dari rata-rata 85 unit kapal rawai tuna yang beroperasi di perairan Samudera Hindia. Hasil tangkapan ikan cucut (Requiem Shark sp.) tertinggi terjadi pada bulan Juli sampai dengan Agustus. Hasil tangkapan ini berkaitan dengan kondisi cuaca (Requiem Shark sp.) pada saat nelayan melakukan penangkapan ikan di laut. Tuna long lines fisheries have more contributed on the catch of Shark (Requiem Shark sp.) in the Indian Ocean. Most of catch from tuna long lines landed at two main landing sites of tuna long line which operated in the Indian Ocean were Pelabuhan Ratu and Cilacap. This study was conducted at that two landing sites during 2004. The result showed that Shark (RequiemShark sp.) catch composition on tuna long line was dominated by blue Shark, Prionace glauca (40 to 90%), while other Sharks i.e. silky Shark (Carcharhinus falciformis), spot tail Shark (Carcharhinus sorrah), big eye thresher (Alopias superciliosus), pelagic thresher (Alopias pelagicus), and mako Shark (Isurus sp.) between 3 to 30% from the total catch of Shark (Requiem Shark sp.). Percentage catch of Sharks (Requiem Shark sp.) againts total catch of tuna surface long line during 2004 was ranging 5 to 25% from everage of 85 unit of tuna long line boat that operated in the Indian Ocean. Catch fluctuation related with the weather conditon when the fishers are fishing activity at sea. The high catch of Shark (Requiem Shark sp.) was occur on July until August