The Experts below are selected from a list of 123 Experts worldwide ranked by ideXlab platform
Kari I Kivirikko - One of the best experts on this subject based on the ideXlab platform.
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tissue specific changes in the Hydroxylysine content and cross links of collagens and alterations in fibril morphology in lysyl hydroxylase 1 knock out mice
Journal of Biological Chemistry, 2007Co-Authors: Kati Takaluoma, Raija Sormunen, Johanna Myllyharju, Kari I Kivirikko, Ruud A. Bank, Marjo Hyry, Juha Lantto, Raija SoininenAbstract:Abstract We have generated mice with targeted inactivation of the Plod1 gene for lysyl hydroxylase 1 (LH1). Its human mutations cause Ehlers-Danlos syndrome VIA (EDS VIA) characterized by muscular hypotonia, joint laxity, and kyphoscoliosis. The Plod1-/- mice are flaccid and have gait abnormalities. About 15% of them died because of aortic rupture and smooth muscle cells in non-ruptured Plod1-/- aortas showed degenerative changes. Collagen fibrils in the Plod1-/- aorta and skin had an abnormal morphology. The LH activity level in the Plod1-/- skin and aorta samples was 35–45% of that in the wild type. The Hydroxylysine content was decreased in all the Plod1-/- tissues, ranging from 22% of that in the wild type in the skin to 75 and 86% in the femur and lung. The hydroxylysylpyridinoline crosslinks likewise showed decreases in all the Plod1-/- tissues, ranging from 28 and 33% of that in the wild type in the aorta and cornea to 47 and 59% in femur and tendon, while lysylpyridinolines were increased. The Hydroxylysines found in the Plod1-/- collagens and their cross-links were evidently synthesized by the other two LH isoenzymes. Few data are available on abnormalities in EDS VIA tissues other than the skin. Plod1-/- mice offer an in vivo model for systematic analysis of the tissue-specific consequences of the lack of LH1 activity and may also provide a tool for analyzing the roles of connective tissue in muscle function and the complex interactions occurring in the proper assembly of the extracellular matrix.
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recombinant human type ii collagens with low and high levels of Hydroxylysine and its glycosylated forms show marked differences in fibrillogenesis in vitro
Journal of Biological Chemistry, 1999Co-Authors: Holger Notbohm, Minna Nokelainen, Johanna Myllyharju, Peter P Fietzek, P K Muller, Kari I KivirikkoAbstract:Abstract Type II collagen is the main structural component of hyaline cartilages where it forms networks of thin fibrils that differ in morphology from the much thicker fibrils of type I collagen. We studied here in vitro the formation of fibrils of pepsin-treated recombinant human type II collagen produced in insect cells. Two kinds of type II collagen preparation were used: low Hydroxylysine collagen having 2.0 Hydroxylysine residues/1,000 amino acids, including 1.3 glycosylated Hydroxylysines; and high Hydroxylysine collagen having 19 Hydroxylysines/1,000 amino acids, including 8.9 glycosylated Hydroxylysines. A marked difference in fibril formation was found between these two kinds of collagen preparation, in that the maximal turbidity of the former was reached within 5 min under the standard assay conditions, whereas the absorbance of the latter increased until about 600 min. The critical concentration with the latter was about 10-fold, and the absorbance/microgram collagen incorporated into the fibrils was about one-sixth. The morphology of the fibrils was also different, in that the high Hydroxylysine collagen formed thin fibrils with essentially no interfibril interaction or aggregation, whereas the low Hydroxylysine collagen formed thick fibrils on a background of thin ones. The data thus indicate that regulation of the extents of lysine hydroxylation and Hydroxylysine glycosylation may play a major role in the regulation of collagen fibril formation and the morphology of the fibrils.
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expression and characterization of recombinant human type ii collagens with low and high contents of Hydroxylysine and its glycosylated forms
Matrix Biology, 1998Co-Authors: Minna Nokelainen, Holger Notbohm, Johanna Myllyharju, Peter P Fietzek, Tarja Helaakoski, Taina Pihlajaniemi, Kari I KivirikkoAbstract:Abstract Insect cells coinfected with two baculoviruses, one coding for the proα chains of human type II procollagen and the other for both the α and β subunits of human prolyl 4-hydroxylase, produced the cartilage-specific type II collagen with a stable triple helix. The highest expression levels, up to 50 mg/1 of type II collagen, were obtained in suspension culture using a modified construct in which sequences coding for the signal peptide and N propeptide of type II procollagen had been replaced by those for type III procollagen. The type III N propeptide artificially generated into type II procollagen was found to be cleaved at a much higher rate than the wild-type type II N propeptide, probably because the former interacted poorly with the triple-helical domain of type II procollagen. The amino acid composition of the recombinant type II collagen was very similar to that of the non-recombinant protein, but the Hydroxylysine content was only 17% and that of glycosylated Hydroxylysines was equally low. The Hydroxylysine content was increased to the level found in the non-recombinant collagen by using an additional baculovirus coding for lysyl hydroxylase, and a substantial increase was also found in the glycosylated Hydroxylysine content. No difference in thermal stability was found between the low- and high-Hydroxylysine collagens.
Mario Anastasia - One of the best experts on this subject based on the ideXlab platform.
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Hydroxylysine containing glycoconjugates an efficient synthesis of natural galactosylHydroxylysine gal hyl and glucosylgalactosylHydroxylysine glu gal hyl and of their 5s epimers
Tetrahedron-asymmetry, 2004Co-Authors: Pietro Allevi, Rita Paroni, Andrea Ragusa, Mario AnastasiaAbstract:Abstract The paper reports the first chemical synthesis of α- d -glucopyranosyl-(1→2)-β- d -galactopyranosyl-5- O -Hydroxylysine, a biological marker of bone resorption and of its unnatural (5 S )-epimer, starting from commercial sugars and amino acids. Moreover, the synthetic protocol set-up has resulted in a new procedure for the synthesis of the β- d -galactopyranosyl-5- O -Hydroxylysine and its unnatural (5 S )-epimer.
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a practical and simple synthesis of 2s 5r and 2s 5s 5 Hydroxylysine and of a related α amino acid required for the synthesis of the collagen cross link pyridinoline
Tetrahedron-asymmetry, 2004Co-Authors: Pietro Allevi, Mario AnastasiaAbstract:A four step synthesis of (2S,5R)- and (2S,5S)-5-Hydroxylysine using Williams' glycine template methodology for controlling the stereogenicity at the α-position is reported. This route offers the possibility for the synthesis of all possible isomers of 5-Hydroxylysine and of an important α-amino acidic iodohydrin required for the construction of the hydroxylated side chain of the collagen cross-link pyridinoline.
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the first synthesis of glucosylgalactosyl Hydroxylysine glu gal hyl an important biological indicator of collagen turnover
Bioorganic & Medicinal Chemistry Letters, 2004Co-Authors: Pietro Allevi, Mario Anastasia, Rita Paroni, Andrea RagusaAbstract:Abstract This paper reports the first chemical synthesis of α- d -glucopyranosyl-(1 → 2)-β- d -galactopyranosyl- O -Hydroxylysine, a glycoside of Hydroxylysine important as indicator of skin and bone collagen turnover, starting with commercial compounds.
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synthesis of all four possible stereoisomers of 5 Hydroxylysine
Tetrahedron-asymmetry, 2000Co-Authors: Pietro Allevi, Mario AnastasiaAbstract:Abstract A simple protocol for the transformation of l - and d -glutamic acids into the enantiopure forms of all four isomers of 5-Hydroxylysine is described.
Xuechen Li - One of the best experts on this subject based on the ideXlab platform.
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a fluorogenic probe for recognizing 5 Hydroxylysine inspired by serine threonine ligation
Chemical Communications, 2014Co-Authors: Chun Ling Tung, Jianchao Xu, Xuechen LiAbstract:The 5-lysyl-hydroxylation has been found among protein post-translational modifications. In this report, we have devised a fluorescence turn-on probe which allows for selectively recognizing 5-Hydroxylysine-containing peptides.
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A fluorogenic probe for recognizing 5-Hydroxylysine inspired by serine/threonine ligation.
Chemical Communications, 2013Co-Authors: Chun Ling Tung, Jianchao Xu, Xuechen LiAbstract:The 5-lysyl-hydroxylation has been found among protein post-translational modifications. In this report, we have devised a fluorescence turn-on probe which allows for selectively recognizing 5-Hydroxylysine-containing peptides.
Pietro Allevi - One of the best experts on this subject based on the ideXlab platform.
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Hydroxylysine containing glycoconjugates an efficient synthesis of natural galactosylHydroxylysine gal hyl and glucosylgalactosylHydroxylysine glu gal hyl and of their 5s epimers
Tetrahedron-asymmetry, 2004Co-Authors: Pietro Allevi, Rita Paroni, Andrea Ragusa, Mario AnastasiaAbstract:Abstract The paper reports the first chemical synthesis of α- d -glucopyranosyl-(1→2)-β- d -galactopyranosyl-5- O -Hydroxylysine, a biological marker of bone resorption and of its unnatural (5 S )-epimer, starting from commercial sugars and amino acids. Moreover, the synthetic protocol set-up has resulted in a new procedure for the synthesis of the β- d -galactopyranosyl-5- O -Hydroxylysine and its unnatural (5 S )-epimer.
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a practical and simple synthesis of 2s 5r and 2s 5s 5 Hydroxylysine and of a related α amino acid required for the synthesis of the collagen cross link pyridinoline
Tetrahedron-asymmetry, 2004Co-Authors: Pietro Allevi, Mario AnastasiaAbstract:A four step synthesis of (2S,5R)- and (2S,5S)-5-Hydroxylysine using Williams' glycine template methodology for controlling the stereogenicity at the α-position is reported. This route offers the possibility for the synthesis of all possible isomers of 5-Hydroxylysine and of an important α-amino acidic iodohydrin required for the construction of the hydroxylated side chain of the collagen cross-link pyridinoline.
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the first synthesis of glucosylgalactosyl Hydroxylysine glu gal hyl an important biological indicator of collagen turnover
Bioorganic & Medicinal Chemistry Letters, 2004Co-Authors: Pietro Allevi, Mario Anastasia, Rita Paroni, Andrea RagusaAbstract:Abstract This paper reports the first chemical synthesis of α- d -glucopyranosyl-(1 → 2)-β- d -galactopyranosyl- O -Hydroxylysine, a glycoside of Hydroxylysine important as indicator of skin and bone collagen turnover, starting with commercial compounds.
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synthesis of all four possible stereoisomers of 5 Hydroxylysine
Tetrahedron-asymmetry, 2000Co-Authors: Pietro Allevi, Mario AnastasiaAbstract:Abstract A simple protocol for the transformation of l - and d -glutamic acids into the enantiopure forms of all four isomers of 5-Hydroxylysine is described.
Johanna Myllyharju - One of the best experts on this subject based on the ideXlab platform.
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tissue specific changes in the Hydroxylysine content and cross links of collagens and alterations in fibril morphology in lysyl hydroxylase 1 knock out mice
Journal of Biological Chemistry, 2007Co-Authors: Kati Takaluoma, Raija Sormunen, Johanna Myllyharju, Kari I Kivirikko, Ruud A. Bank, Marjo Hyry, Juha Lantto, Raija SoininenAbstract:Abstract We have generated mice with targeted inactivation of the Plod1 gene for lysyl hydroxylase 1 (LH1). Its human mutations cause Ehlers-Danlos syndrome VIA (EDS VIA) characterized by muscular hypotonia, joint laxity, and kyphoscoliosis. The Plod1-/- mice are flaccid and have gait abnormalities. About 15% of them died because of aortic rupture and smooth muscle cells in non-ruptured Plod1-/- aortas showed degenerative changes. Collagen fibrils in the Plod1-/- aorta and skin had an abnormal morphology. The LH activity level in the Plod1-/- skin and aorta samples was 35–45% of that in the wild type. The Hydroxylysine content was decreased in all the Plod1-/- tissues, ranging from 22% of that in the wild type in the skin to 75 and 86% in the femur and lung. The hydroxylysylpyridinoline crosslinks likewise showed decreases in all the Plod1-/- tissues, ranging from 28 and 33% of that in the wild type in the aorta and cornea to 47 and 59% in femur and tendon, while lysylpyridinolines were increased. The Hydroxylysines found in the Plod1-/- collagens and their cross-links were evidently synthesized by the other two LH isoenzymes. Few data are available on abnormalities in EDS VIA tissues other than the skin. Plod1-/- mice offer an in vivo model for systematic analysis of the tissue-specific consequences of the lack of LH1 activity and may also provide a tool for analyzing the roles of connective tissue in muscle function and the complex interactions occurring in the proper assembly of the extracellular matrix.
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recombinant human type ii collagens with low and high levels of Hydroxylysine and its glycosylated forms show marked differences in fibrillogenesis in vitro
Journal of Biological Chemistry, 1999Co-Authors: Holger Notbohm, Minna Nokelainen, Johanna Myllyharju, Peter P Fietzek, P K Muller, Kari I KivirikkoAbstract:Abstract Type II collagen is the main structural component of hyaline cartilages where it forms networks of thin fibrils that differ in morphology from the much thicker fibrils of type I collagen. We studied here in vitro the formation of fibrils of pepsin-treated recombinant human type II collagen produced in insect cells. Two kinds of type II collagen preparation were used: low Hydroxylysine collagen having 2.0 Hydroxylysine residues/1,000 amino acids, including 1.3 glycosylated Hydroxylysines; and high Hydroxylysine collagen having 19 Hydroxylysines/1,000 amino acids, including 8.9 glycosylated Hydroxylysines. A marked difference in fibril formation was found between these two kinds of collagen preparation, in that the maximal turbidity of the former was reached within 5 min under the standard assay conditions, whereas the absorbance of the latter increased until about 600 min. The critical concentration with the latter was about 10-fold, and the absorbance/microgram collagen incorporated into the fibrils was about one-sixth. The morphology of the fibrils was also different, in that the high Hydroxylysine collagen formed thin fibrils with essentially no interfibril interaction or aggregation, whereas the low Hydroxylysine collagen formed thick fibrils on a background of thin ones. The data thus indicate that regulation of the extents of lysine hydroxylation and Hydroxylysine glycosylation may play a major role in the regulation of collagen fibril formation and the morphology of the fibrils.
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expression and characterization of recombinant human type ii collagens with low and high contents of Hydroxylysine and its glycosylated forms
Matrix Biology, 1998Co-Authors: Minna Nokelainen, Holger Notbohm, Johanna Myllyharju, Peter P Fietzek, Tarja Helaakoski, Taina Pihlajaniemi, Kari I KivirikkoAbstract:Abstract Insect cells coinfected with two baculoviruses, one coding for the proα chains of human type II procollagen and the other for both the α and β subunits of human prolyl 4-hydroxylase, produced the cartilage-specific type II collagen with a stable triple helix. The highest expression levels, up to 50 mg/1 of type II collagen, were obtained in suspension culture using a modified construct in which sequences coding for the signal peptide and N propeptide of type II procollagen had been replaced by those for type III procollagen. The type III N propeptide artificially generated into type II procollagen was found to be cleaved at a much higher rate than the wild-type type II N propeptide, probably because the former interacted poorly with the triple-helical domain of type II procollagen. The amino acid composition of the recombinant type II collagen was very similar to that of the non-recombinant protein, but the Hydroxylysine content was only 17% and that of glycosylated Hydroxylysines was equally low. The Hydroxylysine content was increased to the level found in the non-recombinant collagen by using an additional baculovirus coding for lysyl hydroxylase, and a substantial increase was also found in the glycosylated Hydroxylysine content. No difference in thermal stability was found between the low- and high-Hydroxylysine collagens.
