Photolysis of pyridinoline, a cross-linking amino acid of collagen, by ultraviolet light

1982 ◽  
Vol 60 (5) ◽  
pp. 525-529 ◽  
Author(s):  
Sachiko Sakura ◽  
Daisaburo Fujimoto ◽  
Kikuo Sakamoto ◽  
Akio Mizuno ◽  
Katsutoshi Motegi
Keyword(s):  
Amino Acid ◽  
Ultraviolet Light ◽  
Alkaline Solution ◽  
Absorption Maximum ◽  
Acidic Solution ◽  
Cross Linking ◽  
Neutral Solution ◽  
Pyridinium Ring ◽  
Optimum Wavelength ◽  
Amino Acid Analyser

Pyridinoline, a cross-linking amino acid of collagen, was degraded by irradiation of ultraviolet light. The decomposition rate varied with pH of the solution and wavelength of irradiation light. The maximum of the degradation rate at individual pH coincides with the ultraviolet absorption maximum. Namely, it was maximally degraded by irradiation at 295 nm in acidic solution and at 325 nm in neutral and alkaline solution. At the optimum wavelength, the photolysis occurred more rapidly in neutral and alkaline solution than in acidic solution. The quantum yield in neutral solution was approximately 0.11 and independent of wavelength. One of the photolysis products was identified as hydroxylysine on an amino acid analyser, indicating that the cleavage of the pyridinium ring occurred.

Synthesis of Poly(vinyl alcohol)/Chitosan/Silicon Oxide Beads Untreated and Glutaraldehyde Treated

2014 ◽  
Vol 893 ◽  
pp. 27-30
Author(s):  
Syazwan Liyana Sulaiman ◽  
Muhamad Subri Abu Bakar ◽  
Sufizar Ahmad ◽  
Hariati Taib
Keyword(s):  
Alkaline Solution ◽  
Silicon Oxide ◽  
Acidic Solution ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Poly Vinyl Alcohol ◽  
Cross Linking ◽  
Distilled Water ◽  
Swelling Behaviour ◽  
Promising Alternative

Synthesised PVA/CS/SiO2 beads had been considered as a promising alternative to conventional means of heavy metal removal. The PVA/CS/SiO2 beads were successfully synthesised through a simple dropwise method and different ratio of cross-linking agent, glutaraldehyde (GLA) of 0, 0.25M and 0.5M were used to cross-link the PVA/CS/SiO2 beads. Solubility and swelling behavior of the beads were also investigated within the prescribed time of 24h in three different medium of acidic, distilled water and alkaline solution. Result of solubility test showed that PVA/CS/SiO2 beads without GLA dissolves in acidic medium but insoluble in distilled water and alkaline solution. Meanwhile, the PVA/CS/SiO2 beads cross-linked with GLA did not dissolve in all three mediums. The swelling test revealed that PVA/CS/SiO2 beads without cross-linked with GLA showed the highest of swelling in acidic solution which was 225.2% and PVA/CS/SiO2 beads cross-linked with 0.5M GLA recorded the lowest of swelling in acidic solution which was 98.6%. This concluded that as the cross-linking ratio increased, the swelling behaviour of the PVA/CS/SiO2 beads decreased.

Clinical Evaluation of Radio-Labelled Bleomycin for Tumor Detection

1978 ◽  
Vol 17 (06) ◽  
pp. 238-248
Author(s):  
H. Beekhuis ◽  
M.A.P.C. van de Poll ◽  
A. Versluis ◽  
H. Jurjens ◽  
M.G. Woldring ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
Acidic Solution ◽  
Tumor Detection ◽  
Neutral Solution ◽  
Normal Tissues ◽  
Patients With Cancer ◽  
Tumor Bearing

Investigations with bleomycin labelled with radionuclides other than 57Co in patients with cancer and in tumor-bearing animals are described. In patients 57Co-bleo appears to be a better tumor-seeking radiopharmaceutical than 111In-bleo, 99mTc-bleo or 197Hg-bleo. This can be explained by a higher stability in vivo and a better tumor-seeking property of 57Co-bleo and less disturbing activity in the cardiac pool and in bone and other normal tissues when assessing the scintigram.Results with 111In-bleo labelled in acidic solution are not essentially different from those with 111In-bleo labelled in neutral solution.Results of 197Hg-bleo are almost identical with those of 197HgCl2 regarding the tumor-seeking effect as well as the distribution in normal tissues and organs. Probably the complex of 197Hg to bleomycin is not stable in vivo. The superiority of 57Co-bleo over 99mTc-bleo, 197Hg-bleo and also over 67Cu-bleo is confirmed by experiments on tumor bearing animals.We may conclude that the indication for use of bleomycin as a tumor-seeking pharmaceutical labelled with 111In, 99mTc, 197Hg or 67Cu seems to be very limited.

Diversity of Primary Structures of the Carboxy-terminal Regions of Mammalian Fibrinogen Aα-Chains

1993 ◽  
Vol 69 (04) ◽  
pp. 351-360 ◽  
Author(s):  
Masahiro Murakawa ◽  
Takashi Okamura ◽  
Takumi Kamura ◽  
Tsunefumi Shibuya ◽  
Mine Harada ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rhesus Monkey ◽  
Syrian Hamster ◽  
Tandem Repeats ◽  
Mammalian Species ◽  
Amino Acid Sequences ◽  
Point Of View ◽  
Cross Linking ◽  
Amino Terminal ◽  
Rgd Sequence

SummaryThe partial amino acid sequences of fibrinogen Aα-chains from five mammalian species have been inferred by means of the polymerase chain reaction (PCR). From the genomic DNA of the rhesus monkey, pig, dog, mouse and Syrian hamster, the DNA fragments coding for α-C domains in the Aα-chains were amplified and sequenced. In all species examined, four cysteine residues were always conserved at the homologous positions. The carboxy- and amino-terminal portions of the α-C domains showed a considerable homology among the species. However, the sizes of the middle portions, which corresponded to the internal repeat structures, showed an apparent variability because of several insertions and/or deletions. In the rhesus monkey, pig, mouse and Syrian hamster, 13 amino acid tandem repeats fundamentally similar to those in humans and the rat were identified. In the dog, however, tandem repeats were found to consist of 18 amino acids, suggesting an independent multiplication of the canine repeats. The sites of the α-chain cross-linking acceptor and α2-plasmin inhibitor cross-linking donor were not always evolutionally conserved. The arginyl-glycyl-aspartic acid (RGD) sequence was not found in the amplified region of either the rhesus monkey or the pig. In the canine α-C domain, two RGD sequences were identified at the homologous positions to both rat and human RGD S. In the Syrian hamster, a single RGD sequence was found at the same position to that of the rat. Triplication of the RGD sequences was seen in the murine fibrinogen α-C domain around the homologous site to the rat RGDS sequence. These findings are of some interest from the point of view of structure-function and evolutionary relationships in the mammalian fibrinogen Aα-chains.

Statistical Force-Field for Structural Modeling Using Chemical Cross-Linking/mass Spectrometry Distance Constraints

2018 ◽  
Author(s):  
Allan J. R. Ferrari ◽  
Fabio C. Gozzo ◽  
Leandro Martinez
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Force Field ◽  
Protein Structures ◽  
Protein Structure Determination ◽  
Structural Modeling ◽  
Cross Linking ◽  
Amino Acid Residues ◽  
Distance Constraints ◽  
Chemical Cross Linking

<div><p>Chemical cross-linking/Mass Spectrometry (XLMS) is an experimental method to obtain distance constraints between amino acid residues, which can be applied to structural modeling of tertiary and quaternary biomolecular structures. These constraints provide, in principle, only upper limits to the distance between amino acid residues along the surface of the biomolecule. In practice, attempts to use of XLMS constraints for tertiary protein structure determination have not been widely successful. This indicates the need of specifically designed strategies for the representation of these constraints within modeling algorithms. Here, a force-field designed to represent XLMS-derived constraints is proposed. The potential energy functions are obtained by computing, in the database of known protein structures, the probability of satisfaction of a topological cross-linking distance as a function of the Euclidean distance between amino acid residues. The force-field can be easily incorporated into current modeling methods and software. In this work, the force-field was implemented within the Rosetta ab initio relax protocol. We show a significant improvement in the quality of the models obtained relative to current strategies for constraint representation. This force-field contributes to the long-desired goal of obtaining the tertiary structures of proteins using XLMS data. Force-field parameters and usage instructions are freely available at http://m3g.iqm.unicamp.br/topolink/xlff <br></p></div><p></p><p></p>

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