The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Tetsuo Inoue - One of the best experts on this subject based on the ideXlab platform.
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direct measurement of Crosslinks pyridinoline deoxypyridinoline and pentosidine in the hydrolysate of tissues using high performance liquid chromatography
Analytical Biochemistry, 1995Co-Authors: Masaaki Takahashi, Hironobu Hoshino, Kazuhiro Kushida, Tetsuo InoueAbstract:Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) are mature Crosslinks which maintain the structure of the collagen fibril. Pentosidine (Pen) is a senescent crosslink and one of the advanced glycation end products. We developed a direct and one-injection method to measure Pyr, Dpyr, and Pen in the hydrolysate of tissues using reversed-phase high-performance liquid chromatography. Using a linear gradient of acetonitrile and a cleaning step, the objective Crosslinks were well separated and continuously and automatically assayed. Recovery rates of Pyr, Dpyr, and Pen were 95–116, 94–110, and 92–120%, respectively (n= 5). The intraassay coefficients of variation for Pyr, Dpyr, and Pen were 5.3, 5.8, and 4.3%, respectively (n= 5), and the interassay coefficients of variation for Pyr, Dpyr, and Pen were 3.5, 4.6, and 5.7%, respectively (n= 5). Linear regression analysis showed the linearity (r= 0.999) of calibration line for each Pyr, Dpyr, and Pen. We measured the content of these Crosslinks in the tissues from the young and old subjects. There was no difference in the content of Pyr and Dpyr between the young and the old group. On the other hand, the content of Pen in the old group was extremely higher than that in the young group. We demonstrated the direct method for measuring two kinds of major Crosslinks which have different characters and believe that this method will be useful in determining the content of these Crosslinks in tissues under various conditions.
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Quantitation of the Crosslinks, pyridinoline, deoxypyridinoline and pentosidine, in human aorta with dystrophic calcification
Atherosclerosis, 1995Co-Authors: Hironobu Hoshino, Masaaki Takahashi, Kazuhiro Kushida, Tsuyoshi Ohishi, K. Kawana, Tetsuo InoueAbstract:Pyridinoline and, its minor analogue deoxypyridinoline, are trifunctional Crosslinks of mature collagen in the connective tissues. Pentosidine, a new type of fluorescent crosslink, is possibly one of the senescent Crosslinks but its function and metabolism are still unclear. In this study, we quantitated the Crosslinks, pyridinoline, deoxypyridinoline and pentosidine, in human aorta which were obtained from 21 autopsy cases. In each case, the existence of dystrophic calcification in the aorta and complications (diabetes, chronic renal failure and hypertension) were examined. The determination of the content of the three Crosslinks was carried out using high performance liquid chromatography (HPLC) analysis. In calcified lesions, the amount of deoxypyridinoline/collagen showed a decrease and the amount of deoxypyridinoline/pyridinoline showed a prominent decrease compared to those in non-calcified lesions (deoxypyridinoline/ collagen, P < 0.005; deoxypyridinoline/pyridinoline, P < 0.0001). In non-calcified lesions without complications, the amount of pentosidine/pyridinoline and that of pentosidine/deoxypyridinoline significantly increased with age (pentosidine/pyridinoline, r = 0.704, P < 0.05; pentosidine/deoxypyridinoline, r = 0.624, P < 0.05). This result suggests a possible relationship between dystrophic calcification and crosslink formation of collagen in human aorta.
Richard Brimacombe - One of the best experts on this subject based on the ideXlab platform.
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new features of 23s ribosomal rna folding the long helix 41 42 makes a u turn inside the ribosome
RNA, 1998Co-Authors: Pavel V Baranov, Richard Brimacombe, A A Bogdanov, Olga L Gurvich, O A DontsovaAbstract:23S rRNA from Escherichia coli was cleaved at single internucleotide bonds using ribonuclease H in the presence of appropriate chimeric oligonucleotides; the individual cleavage sites were between residues 384 and 385, 867 and 868, 1045 and 1046, and 2510 and 2511, with an additional fortuitous cleavage at positions 1117 and 1118. In each case, the 3' terminus of the 5' fragment was ligated to radioactively labeled 4-thiouridine 5'-,3'-biphosphate ("psUp"), and the cleaved 23S rRNA carrying this label was reconstituted into 50S subunits. The 50S subunits were able to associate normally with 30S subunits to form 70S ribosomes. Intra-RNA Crosslinks from the 4-thiouridine residues were induced by irradiation at 350 nm, and the crosslink sites within the 23S rRNA were analyzed. The rRNA molecules carrying psUp at positions 867 and 1117 showed Crosslinks to nearby positions on the opposite strand of the same double helix where the cleavage was located, and no crosslinking was detected from position 2510. In contrast, the rRNA carrying psUp at position 384 showed crosslinking to nt 420 (and sometimes also to 416 and 425) in the neighboring helix in 23S rRNA, and the rRNA with psUp at position 1045 gave a crosslink to residue 993. The latter crosslink demonstrates that the long helix 41-42 of the 23S rRNA (which carries the region associated with GTPase activity) must double back on itself, forming a "U-turn" in the ribosome. This result is discussed in terms of the topography of the GTPase region in the 50S subunit, and its relation to the locations of the 5S rRNA and the peptidyl transferase center.
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the path of mrna through the bacterial ribosome a site directed crosslinking study using new photoreactive derivatives of guanosine and uridine
RNA, 1997Co-Authors: Petr V. Sergiev, Inna N. Lavrik, V A Wlasoff, S S Dokudovskaya, O A Dontsova, A A Bogdanov, Richard BrimacombeAbstract:Two new photoreactive nucleotide derivatives have been applied in site-directed crosslinking studies with mRNA analogues. 6-Thioguanosine triphosphate or 5-methyleneaminouridine triphosphate was incorporated into mRNA analogues by T7 transcription; after transcription, the 5-methyleneaminouridine residues were converted to a diazirine derivative. mRNA analogues carrying either 6-thioguanosine or the diazirine derivative were bound to Escherichia coli ribosomes in the presence of tRNA(f)(Met), and photo-crosslinking was induced by irradiation at 350 nm. With 6-thioguanosine, specific Crosslinks were observed from downstream positions +8 or +9 of the mRNA to nt 1196 in helix 34 of the 16S rRNA, and from position +12 to nt 530 in helix 18. With the diazirine derivative, a crosslink from position +2 (within the AUG codon) to nt 926 in helix 28 was found. Taken together with previous data obtained from downstream sites in mRNA analogues carrying 4-thiouridine residues, specific Crosslinks have now been identified from downstream mRNA positions +2, +4, +6, +7, +8, +9, +11, and +12. The data confirm that the three 16S rRNA regions involved-helices 18, 28, and 34-are in the direct neighborhood of the decoding area of the 30S subunit.
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loop iv of 5s ribosomal rna has contacts both to domain ii and to domain v of the 23s rna
RNA, 1996Co-Authors: S S Dokudovskaya, O A Dontsova, A A Bogdanov, O V Shpanchenko, Richard BrimacombeAbstract:An analogue of 55 rRNA, containing a random distribution of thiouridine residues in place of normal uridine, was prepared by T7 transcription from a suitable DNA template. The modified RNA molecule was reconstituted into 505 or 705 ribosomes, and the thiouridine residues were activated by irradiation at 350 nm. Crosslinks generated between the 55 and 235 RNA were analyzed by our standard procedures. Two crosslink sites were identified, one to residue A-960 at the loop-end of helix 39 in Domain II, and the other to C-2475 at the loopend of helix 89 in Domain V of the 235 RNA. Both Crosslinks involved residue U-89 of the 55 RNA, that in Domain V corresponding to the principal crosslink found in a previously published series of experiments. The relative intensities of the two crosslink sites were found to be highly dependent on individual preparations of 505 ribosomal proteins and 235 RNA. The results are discussed in terms of the three-dimensional folding and dynamics of the 235 RNA within the 505 subunit.
O A Dontsova - One of the best experts on this subject based on the ideXlab platform.
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new features of 23s ribosomal rna folding the long helix 41 42 makes a u turn inside the ribosome
RNA, 1998Co-Authors: Pavel V Baranov, Richard Brimacombe, A A Bogdanov, Olga L Gurvich, O A DontsovaAbstract:23S rRNA from Escherichia coli was cleaved at single internucleotide bonds using ribonuclease H in the presence of appropriate chimeric oligonucleotides; the individual cleavage sites were between residues 384 and 385, 867 and 868, 1045 and 1046, and 2510 and 2511, with an additional fortuitous cleavage at positions 1117 and 1118. In each case, the 3' terminus of the 5' fragment was ligated to radioactively labeled 4-thiouridine 5'-,3'-biphosphate ("psUp"), and the cleaved 23S rRNA carrying this label was reconstituted into 50S subunits. The 50S subunits were able to associate normally with 30S subunits to form 70S ribosomes. Intra-RNA Crosslinks from the 4-thiouridine residues were induced by irradiation at 350 nm, and the crosslink sites within the 23S rRNA were analyzed. The rRNA molecules carrying psUp at positions 867 and 1117 showed Crosslinks to nearby positions on the opposite strand of the same double helix where the cleavage was located, and no crosslinking was detected from position 2510. In contrast, the rRNA carrying psUp at position 384 showed crosslinking to nt 420 (and sometimes also to 416 and 425) in the neighboring helix in 23S rRNA, and the rRNA with psUp at position 1045 gave a crosslink to residue 993. The latter crosslink demonstrates that the long helix 41-42 of the 23S rRNA (which carries the region associated with GTPase activity) must double back on itself, forming a "U-turn" in the ribosome. This result is discussed in terms of the topography of the GTPase region in the 50S subunit, and its relation to the locations of the 5S rRNA and the peptidyl transferase center.
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the path of mrna through the bacterial ribosome a site directed crosslinking study using new photoreactive derivatives of guanosine and uridine
RNA, 1997Co-Authors: Petr V. Sergiev, Inna N. Lavrik, V A Wlasoff, S S Dokudovskaya, O A Dontsova, A A Bogdanov, Richard BrimacombeAbstract:Two new photoreactive nucleotide derivatives have been applied in site-directed crosslinking studies with mRNA analogues. 6-Thioguanosine triphosphate or 5-methyleneaminouridine triphosphate was incorporated into mRNA analogues by T7 transcription; after transcription, the 5-methyleneaminouridine residues were converted to a diazirine derivative. mRNA analogues carrying either 6-thioguanosine or the diazirine derivative were bound to Escherichia coli ribosomes in the presence of tRNA(f)(Met), and photo-crosslinking was induced by irradiation at 350 nm. With 6-thioguanosine, specific Crosslinks were observed from downstream positions +8 or +9 of the mRNA to nt 1196 in helix 34 of the 16S rRNA, and from position +12 to nt 530 in helix 18. With the diazirine derivative, a crosslink from position +2 (within the AUG codon) to nt 926 in helix 28 was found. Taken together with previous data obtained from downstream sites in mRNA analogues carrying 4-thiouridine residues, specific Crosslinks have now been identified from downstream mRNA positions +2, +4, +6, +7, +8, +9, +11, and +12. The data confirm that the three 16S rRNA regions involved-helices 18, 28, and 34-are in the direct neighborhood of the decoding area of the 30S subunit.
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loop iv of 5s ribosomal rna has contacts both to domain ii and to domain v of the 23s rna
RNA, 1996Co-Authors: S S Dokudovskaya, O A Dontsova, A A Bogdanov, O V Shpanchenko, Richard BrimacombeAbstract:An analogue of 55 rRNA, containing a random distribution of thiouridine residues in place of normal uridine, was prepared by T7 transcription from a suitable DNA template. The modified RNA molecule was reconstituted into 505 or 705 ribosomes, and the thiouridine residues were activated by irradiation at 350 nm. Crosslinks generated between the 55 and 235 RNA were analyzed by our standard procedures. Two crosslink sites were identified, one to residue A-960 at the loop-end of helix 39 in Domain II, and the other to C-2475 at the loopend of helix 89 in Domain V of the 235 RNA. Both Crosslinks involved residue U-89 of the 55 RNA, that in Domain V corresponding to the principal crosslink found in a previously published series of experiments. The relative intensities of the two crosslink sites were found to be highly dependent on individual preparations of 505 ribosomal proteins and 235 RNA. The results are discussed in terms of the three-dimensional folding and dynamics of the 235 RNA within the 505 subunit.
Masaaki Takahashi - One of the best experts on this subject based on the ideXlab platform.
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direct measurement of Crosslinks pyridinoline deoxypyridinoline and pentosidine in the hydrolysate of tissues using high performance liquid chromatography
Analytical Biochemistry, 1995Co-Authors: Masaaki Takahashi, Hironobu Hoshino, Kazuhiro Kushida, Tetsuo InoueAbstract:Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) are mature Crosslinks which maintain the structure of the collagen fibril. Pentosidine (Pen) is a senescent crosslink and one of the advanced glycation end products. We developed a direct and one-injection method to measure Pyr, Dpyr, and Pen in the hydrolysate of tissues using reversed-phase high-performance liquid chromatography. Using a linear gradient of acetonitrile and a cleaning step, the objective Crosslinks were well separated and continuously and automatically assayed. Recovery rates of Pyr, Dpyr, and Pen were 95–116, 94–110, and 92–120%, respectively (n= 5). The intraassay coefficients of variation for Pyr, Dpyr, and Pen were 5.3, 5.8, and 4.3%, respectively (n= 5), and the interassay coefficients of variation for Pyr, Dpyr, and Pen were 3.5, 4.6, and 5.7%, respectively (n= 5). Linear regression analysis showed the linearity (r= 0.999) of calibration line for each Pyr, Dpyr, and Pen. We measured the content of these Crosslinks in the tissues from the young and old subjects. There was no difference in the content of Pyr and Dpyr between the young and the old group. On the other hand, the content of Pen in the old group was extremely higher than that in the young group. We demonstrated the direct method for measuring two kinds of major Crosslinks which have different characters and believe that this method will be useful in determining the content of these Crosslinks in tissues under various conditions.
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Quantitation of the Crosslinks, pyridinoline, deoxypyridinoline and pentosidine, in human aorta with dystrophic calcification
Atherosclerosis, 1995Co-Authors: Hironobu Hoshino, Masaaki Takahashi, Kazuhiro Kushida, Tsuyoshi Ohishi, K. Kawana, Tetsuo InoueAbstract:Pyridinoline and, its minor analogue deoxypyridinoline, are trifunctional Crosslinks of mature collagen in the connective tissues. Pentosidine, a new type of fluorescent crosslink, is possibly one of the senescent Crosslinks but its function and metabolism are still unclear. In this study, we quantitated the Crosslinks, pyridinoline, deoxypyridinoline and pentosidine, in human aorta which were obtained from 21 autopsy cases. In each case, the existence of dystrophic calcification in the aorta and complications (diabetes, chronic renal failure and hypertension) were examined. The determination of the content of the three Crosslinks was carried out using high performance liquid chromatography (HPLC) analysis. In calcified lesions, the amount of deoxypyridinoline/collagen showed a decrease and the amount of deoxypyridinoline/pyridinoline showed a prominent decrease compared to those in non-calcified lesions (deoxypyridinoline/ collagen, P < 0.005; deoxypyridinoline/pyridinoline, P < 0.0001). In non-calcified lesions without complications, the amount of pentosidine/pyridinoline and that of pentosidine/deoxypyridinoline significantly increased with age (pentosidine/pyridinoline, r = 0.704, P < 0.05; pentosidine/deoxypyridinoline, r = 0.624, P < 0.05). This result suggests a possible relationship between dystrophic calcification and crosslink formation of collagen in human aorta.
Hironobu Hoshino - One of the best experts on this subject based on the ideXlab platform.
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direct measurement of Crosslinks pyridinoline deoxypyridinoline and pentosidine in the hydrolysate of tissues using high performance liquid chromatography
Analytical Biochemistry, 1995Co-Authors: Masaaki Takahashi, Hironobu Hoshino, Kazuhiro Kushida, Tetsuo InoueAbstract:Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) are mature Crosslinks which maintain the structure of the collagen fibril. Pentosidine (Pen) is a senescent crosslink and one of the advanced glycation end products. We developed a direct and one-injection method to measure Pyr, Dpyr, and Pen in the hydrolysate of tissues using reversed-phase high-performance liquid chromatography. Using a linear gradient of acetonitrile and a cleaning step, the objective Crosslinks were well separated and continuously and automatically assayed. Recovery rates of Pyr, Dpyr, and Pen were 95–116, 94–110, and 92–120%, respectively (n= 5). The intraassay coefficients of variation for Pyr, Dpyr, and Pen were 5.3, 5.8, and 4.3%, respectively (n= 5), and the interassay coefficients of variation for Pyr, Dpyr, and Pen were 3.5, 4.6, and 5.7%, respectively (n= 5). Linear regression analysis showed the linearity (r= 0.999) of calibration line for each Pyr, Dpyr, and Pen. We measured the content of these Crosslinks in the tissues from the young and old subjects. There was no difference in the content of Pyr and Dpyr between the young and the old group. On the other hand, the content of Pen in the old group was extremely higher than that in the young group. We demonstrated the direct method for measuring two kinds of major Crosslinks which have different characters and believe that this method will be useful in determining the content of these Crosslinks in tissues under various conditions.
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Quantitation of the Crosslinks, pyridinoline, deoxypyridinoline and pentosidine, in human aorta with dystrophic calcification
Atherosclerosis, 1995Co-Authors: Hironobu Hoshino, Masaaki Takahashi, Kazuhiro Kushida, Tsuyoshi Ohishi, K. Kawana, Tetsuo InoueAbstract:Pyridinoline and, its minor analogue deoxypyridinoline, are trifunctional Crosslinks of mature collagen in the connective tissues. Pentosidine, a new type of fluorescent crosslink, is possibly one of the senescent Crosslinks but its function and metabolism are still unclear. In this study, we quantitated the Crosslinks, pyridinoline, deoxypyridinoline and pentosidine, in human aorta which were obtained from 21 autopsy cases. In each case, the existence of dystrophic calcification in the aorta and complications (diabetes, chronic renal failure and hypertension) were examined. The determination of the content of the three Crosslinks was carried out using high performance liquid chromatography (HPLC) analysis. In calcified lesions, the amount of deoxypyridinoline/collagen showed a decrease and the amount of deoxypyridinoline/pyridinoline showed a prominent decrease compared to those in non-calcified lesions (deoxypyridinoline/ collagen, P < 0.005; deoxypyridinoline/pyridinoline, P < 0.0001). In non-calcified lesions without complications, the amount of pentosidine/pyridinoline and that of pentosidine/deoxypyridinoline significantly increased with age (pentosidine/pyridinoline, r = 0.704, P < 0.05; pentosidine/deoxypyridinoline, r = 0.624, P < 0.05). This result suggests a possible relationship between dystrophic calcification and crosslink formation of collagen in human aorta.