scholarly journals Ehrlich chromogens, probable cross-links in elastin and collagen

1988 ◽  
Vol 252 (2) ◽  
pp. 387-393 ◽  
Author(s):  
P D Kemp ◽  
J E Scott
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Absorption Coefficient ◽  
Cross Linking ◽  
Diazonium Salts ◽  
Gel Chromatography ◽  
Skin Collagen ◽  
Cross Links ◽  
End Group ◽  
15N Abundance

(1) Proteolytic digests of tissue elastin contain material which reacts with dimethylaminobenzaldehyde in acid solution (Ehrlich's reagent) to give a cherry-pink colour. This Ehrlich chromogen(s) [EC(s)] is similar to but not identical with EC(s) previously demonstrated in tissue collagens [Scott, Hughes & Shuttleworth (1979) Biosci. Rep. 1, 611-618]. Both ECs react with diazonium salts in acid to give coloured products. (2) Diazobenzene linked via a phenolic ester to polyacrylamide beads (Biogel P10) has been used to absorb ECs specifically and almost quantitatively from proteolytic digests. The coupled deeply coloured azo-EC-peptides were then recovered after mild alkaline cleavage from the support and purified by gel chromatography. (3) Using 15N-labelled NaNO2, the collagen azo-EC-peptides were prepared, and 15N abundance measured therein. The molar absorption coefficient of the azo-EC group was calculated (18,700) based on the assumption that each azo-EC group contained one 15N atom. (4) Collagen azo-EC-peptides contained glucose and galactose, whereas elastin azo-EC peptides did not. The amino acid patterns of the two peptides were quite different, the former being rich in polar amino acids, the latter containing much alanine. The patterns were compatible with an origin from the cross-linking regions of collagen and elastin respectively. (5) Quantitative (molar) comparisons of the azo-EC group content with amino acid, amino end-group and sugar contents, and azo-EC peptide molecular mass, suggest that a structure is present in the collagen azo-EC-peptides containing two EC groups shared between four peptide chains. Three peptide chains probably meet at each (cross-linking) EC group. (6) Based on this structure, about 15% of adult bovine skin collagen contains EC groups.

scholarly journals Synthesis of Organic Matter in Aqueous Environments Simulating Small Bodies in the Solar System and the Effects of Minerals on Amino Acid Formation

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 32
Author(s):  
Walaa Elmasry ◽  
Yoko Kebukawa ◽  
Kensei Kobayashi
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
Amino Acid ◽  
Solar System ◽  
Acid Formation ◽  
Gel Chromatography ◽  
Small Bodies ◽  
Enhanced Production ◽  
Aqueous Environments ◽  
Heating Duration

The extraterrestrial delivery of organics to primitive Earth has been supported by many laboratory and space experiments. Minerals played an important role in the evolution of meteoritic organic matter. In this study, we simulated aqueous alteration in small bodies by using a solution mixture of H2CO and NH3 in the presence of water at 150 °C under different heating durations, which produced amino acids after acid hydrolysis. Moreover, minerals were added to the previous mixture to examine their catalyzing/inhibiting impact on amino acid formation. Without minerals, glycine was the dominant amino acid obtained at 1 d of the heating experiment, while alanine and β-alanine increased significantly and became dominant after 3 to 7 d. Minerals enhanced the yield of amino acids at short heating duration (1 d); however, they induced their decomposition at longer heating duration (7 d). Additionally, montmorillonite enhanced amino acid production at 1 d, while olivine and serpentine enhanced production at 3 d. Molecular weight distribution in the whole of the products obtained by gel chromatography showed that minerals enhanced both decomposition and combination of molecules. Our results indicate that minerals affected the formation of amino acids in aqueous environments in small Solar System bodies and that the amino acids could have different response behaviors according to different minerals.

Isolation of a Crosslinked Peptide from Hitman Fibrin and Development of a Radioimmunoassay

1979 ◽  
Author(s):  
R. Canfield ◽  
B. Lahiri ◽  
R. D’Alisa ◽  
V. Butler ◽  
H. Nossel ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Factor Xiiia ◽  
Cross Linking ◽  
Edman Degradation ◽  
Cnbr Cleavage ◽  
Normal Hemostasis

Factor XIIIa introduces up to six crossllnklng bonds per molecule of fibrin; the bonds between the γ chains on adjacent fibrin molecules form most rapidly. Since cross linking is essential for normal hemostasis and is likely to be important in tests to detect thrombosis, we have attempted to develop a radioimmunoassay that exhibits specificity for the γ chain crosslinks. The immunogen consisted of a 54 amino acid, crosslinked peptide, isolated from purified human γ-γ chains following CNBr cleavage, gel filtration on Sephadex G-50 and ion-exchange chromatography on SP-Sephadex. Amino acid analysis and Edman degradation through step 24 confirmed the sequence of Chen and Doolittle (Biochemistry 10: i486, 1971), and the two degradation steps that failed to liberate the expected PTH-amino acids matched the reported location of the Gin-Lys crosslinks. Antisera were obtained against this immunogen coupled either to bovine thyroglobulin or bovine serum albumin. All antisera elicited bound immunogen that was covalently coupled to ribonuclease radiolabeled with 125I as a tracer. The unlabeled γ-γ, crosslinked peptide effectively inhibited binding (0.03-0.08 picomoles for 50% inhibition), while with some antisera up to 500 times more of the 27 amino acid γ monomer peptide was required for the same degree of inhibition. Fibrinogen and fragment D also were poor Inhibitors. The results Indicate that it is possible by radioimmunoassay to distinguish the COOH-termlnal region of the γ-γ dlmer from that of uncrosslinked molecules.

scholarly journals Characterization of Genipin-Modified Dentin Collagen

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hiroko Nagaoka ◽  
Hideaki Nagaoka ◽  
Ricardo Walter ◽  
Lee W. Boushell ◽  
Patricia A. Miguez ◽  
...  
Keyword(s):  
Amino Acid ◽  
Lysyl Oxidase ◽  
Biomechanical Properties ◽  
Biochemical Properties ◽  
Cross Linking ◽  
Dependent Manner ◽  
Cross Link ◽  
Concentration Dependent Manner ◽  
Cross Links ◽  
Dentin Collagen

Application of biomodification techniques to dentin can improve its biochemical and biomechanical properties. Several collagen cross-linking agents have been reported to strengthen the mechanical properties of dentin. However, the characteristics of collagen that has undergone agent-induced biomodification are not well understood. The objective of this study was to analyze the effects of a natural cross-linking agent, genipin (GE), on dentin discoloration, collagen stability, and changes in amino acid composition and lysyl oxidase mediated natural collagen cross-links. Dentin collagen obtained from extracted bovine teeth was treated with three different concentrations of GE (0.01%, 0.1%, and 0.5%) for several treatment times (0–24 h). Changes in biochemical properties of NaB3H4-reduced collagen were characterized by amino acid and cross-link analyses. The treatment of dentin collagen with GE resulted in a concentration- and time-dependent pigmentation and stability against bacterial collagenase. The lysyl oxidase-mediated trivalent mature cross-link, pyridinoline, showed no difference among all groups while the major divalent immature cross-link, dehydro-dihydroxylysinonorleucine/its ketoamine in collagen treated with 0.5% GE for 24 h, significantly decreased compared to control (P< 0.05). The newly formed GE-induced cross-links most likely involve lysine and hydroxylysine residues of collagen in a concentration-dependent manner. Some of these cross-links appear to be reducible and stabilized with NaB3H4.

scholarly journals Chemistry of the collagen cross-links. Origin and partial characterization of a putative mature cross-link of collagen

1987 ◽  
Vol 244 (2) ◽  
pp. 303-309 ◽  
Author(s):  
K Barnard ◽  
N D Light ◽  
T J Sims ◽  
A J Bailey
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Partial Characterization ◽  
Cross Link ◽  
Cross Links

The conversion of the reducible divalent cross-links in collagen to non-reducible multivalent cross-links in mature collagen has resulted in the identification of several new amino acids as the putative mature cross-link. None of these compounds has completely satisfied the necessary criteria. We have now isolated an amino acid of high Mr, derived from lysine, that is only present in high-Mr peptides derived from mature collagen. Its increase with age of the tissue correlates with the decrease in the reducible cross-links, and it is present both in mature skin and bone, which are initially cross-linked through the aldimine and oxo-imine divalent cross-link respectively. We propose that this amino acid, as yet incompletely characterized and designated compound M, is a major cross-link of mature collagen.

scholarly journals Some Researches on Histones

1962 ◽  
Vol 45 (4) ◽  
pp. 195-203 ◽  
Author(s):  
J. A. V. Butler
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Experimental Error ◽  
Tissue Specificity ◽  
Basic Amino Acid ◽  
Gel Chromatography ◽  
Rat Tissues ◽  
Calf Thymus ◽  
End Groups ◽  
Starch Gel

The histone extracted from calf thymus glands is a complex system of proteins, which can be fractionated by chromatography on carboxymethyl cellulose columns into three principal fractions (1) very lysine-rich, (2) moderately lysine-rich, (3) arginine-rich. When examined by starch gel chromatography each of these gives more than one band. Methods have been devised for further separation of the components in some cases. The components show characteristic differences in end groups and certain amino acids as well as in their basic character. Histones extracted from various rat tissues can be separated into similar fractions, of which the amino acid analyses are similar to those derived from calf thymus, within the experimental error. To this extent, no species or tissue specificity of the fractionated histones was observed. Although all the histone fractions contain approximately one basic amino acid to three non-basic amino acids their structure is not regular, as Phillips has shown that in certain fractions the number of non-basic groups between two basic groups may vary from 0 to seven or more. The possible functions of histones are discussed.

scholarly journals Generation of guanine–amino acid cross-links by a free radical combination mechanism

2014 ◽  
Vol 16 (23) ◽  
pp. 11729-11736 ◽  
Author(s):  
Yuriy Uvaydov ◽  
Nicholas E. Geacintov ◽  
Vladimir Shafirovich
Keyword(s):  
Free Radical ◽  
Amino Acid ◽  
Side Chain ◽  
Cross Linking ◽  
Two Photon ◽  
Ionization Method ◽  
Cross Links ◽  
Photon Ionization ◽  
Amino Acid Radicals

The key step of DNA–protein cross-linking in vitro is the combination of guanine neutral radicals with side-chain C-centered amino acid radicals produced by a two-photon ionization method.

scholarly journals Collagen cross-linking. Isolation of cross-linked peptides from collagen of chicken bone

1973 ◽  
Vol 135 (3) ◽  
pp. 393-403 ◽  
Author(s):  
D. R. Eyre ◽  
M. J. Glimcher
Keyword(s):  
Amino Acid ◽  
Bone Collagen ◽  
Collagen Molecule ◽  
Cross Linking ◽  
Bacterial Collagenase ◽  
Chicken Bone ◽  
Cross Links ◽  
The Cross ◽  
Significant Pathway ◽  
Carboxy Terminal

Cross-linked peptides were isolated from chicken bone collagen that had been digested with CNBr or with bacterial collagenase. Analyses of 3H radioactivity in disc electrophoretic profiles of the CNBr peptides from bone collagens that had been treated with NaB3H indicated that a major site of intermolecular cross-linking in chicken bone collagen is located between the carboxy-terminal region of an α1 chain and a small CNBr peptide, probably situated near the amino-terminus of an α1 or α2 chain in an adjacent collagen molecule. A small amount of this cross-linked CNBr peptide was isolated from a CNBr digest of chicken bone collagen by column chromatography. Amino acid analysis showed that the CNBr peptide, α1CB6B, the carboxy-terminal peptide of the α1 chain, was the major CNBr peptide in the preparation, and the reduced cross-linking components were identified as hydroxylysinohydroxynorleucine (HylOHNle), with a smaller amount of hydroxylysinonorleucine (HylNle). However, the composition and the low recovery of the cross-linking amino acids suggested that the preparation was a mixture of CNBr peptides α1CB6B and α1CB6B cross-linked to a small CNBr peptide whose identity could not be determined. A small cross-linked peptide was isolated from chicken bone collagen that had been reduced with NaB3H4 and digested with bacterial collagenase. This peptide was the major cross-linked peptide in the digest and contained a stoicheiometric amount of the reduced cross-linking compounds. A peptide which had the same amino acid composition, but contained the cross-linking compounds in their reducible forms, was isolated from a collagenase digest of chicken bone collagen that had not been treated with NaBH4. The absence of the reduced cross-links from this peptide indicates that, at least for the cross-linking site from which the peptide derives, natural reduction is not a significant pathway for biosynthesis of stable cross-links. However, most of the reducible cross-linking component in the peptide appeared to stabilize in the bone collagen by rearrangement from aldimine to ketoamine form.

scholarly journals Chemical compositions of elastins isolated from aortas and pulmonary tissues of humans of different ages

1972 ◽  
Vol 127 (1) ◽  
pp. 261-269 ◽  
Author(s):  
R. John ◽  
J. Thomas
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cross Linking ◽  
Chemical Compositions ◽  
Amino Acid Compositions ◽  
Different Ages ◽  
Older Subjects ◽  
The Cross ◽  
Carbohydrate Contents

1. Elastins were isolated from the visceral pleuras and parenchymas of lungs of humans of different ages. 2. The elastin content of pleuras increased whereas that of parenchymas remained constant with increasing age. 3. The amino acid compositions and carbohydrate contents of elastins isolated from both pulmonary tissues changed in the same way with increasing age of the subjects. These changes were similar to those observed in elastins isolated from the aorta. 4. Similar glycoproteins were isolated from pleuras and aortas, and were more difficult to extract from the elastins of older subjects. Contamination with these glycoproteins was responsible for the changes in composition of elastin, as the age of the tissue from which it was extracted increased. 5. The amount of the cross-linking amino acids desmosine and isodesmosine was lower in elastins isolated from both aorta and pulmonary tissues of senile subjects than those from younger subjects.

scholarly journals The protein–polysaccharide complex of bovine nasal cartilage. Studies on the protein core

1967 ◽  
Vol 105 (2) ◽  
pp. 569-575 ◽  
Author(s):  
A Serafini-Fracassini ◽  
T. J. Peters ◽  
L. Floreani
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Protein Content ◽  
Amino Acid Analysis ◽  
Cetylpyridinium Chloride ◽  
Amino Acid Compositions ◽  
Nasal Cartilage ◽  
Polysaccharide Complex ◽  
End Group

1. Chondromucoprotein from bovine nasal cartilage was purified by cetylpyridinium chloride or by bismuth nitrate in acetone. 2. Amino acid compositions of crude and purified preparations were compared and few differences were found, in spite of the decrease in protein content on purification. 3. Amino acid analysis of bismuth-purified material revealed the existence of four groups of amino acids. Within each group, the amino acids were present in approximately equimolar concentrations. 4. Amino end-group assay on the same material showed six α-DNP derivatives. 5. A molecular weight of 6·3×105 for the protein–polysaccharide complex was calculated from the latter analysis.

The Amino Acid Sequence of Peptides from the Cross-Linking Region of Rat Skin Collagen*

Biochemistry ◽  
1967 ◽  
Vol 6 (3) ◽  
pp. 788-795 ◽  
Author(s):  
Andrew H. Kang ◽  
Paul Bornstein ◽  
Karl A. Piez
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cross Linking ◽  
Rat Skin ◽  
Skin Collagen ◽  
The Cross
Sign in / Sign up

Export Citation Format

Share Document