scholarly journals Chemistry of the collagen cross-links. Isolation and characterization of two intermediate intermolecular cross-links in collagen

1970 ◽  
Vol 117 (5) ◽  
pp. 819-831 ◽  
Author(s):  
A. J. Bailey ◽  
Catherine M. Peach ◽  
L. J. Fowler
Keyword(s):  
Mass Spectrometry ◽  
Large Scale ◽  
High Resolution Mass Spectrometry ◽  
Collagen Fibre ◽  
Reduced Form ◽  
Cross Link ◽  
Isolation And Characterization ◽  
Cross Links

This paper describes the isolation from reduced collagen of two new amino acids believed to be involved, in their non-reduced form, as intermolecular cross-links stabilizing the collagen fibre. The reduction of intact collagen fibrils with tritiated sodium borohydride was found to stabilize the aldehyde-mediated cross-links to acid hydrolysis and thus allowed their location and isolation from acid hydrolysates on an automatic amino acid analyser. Comparison of the radioactive elution patterns from the autoanalyser of collagen treated in various ways before reduction permitted a preliminary classification of the peaks into cross-link precursors, intramolecular and intermolecular cross-links. The techniques employed to isolate the purified components on a large scale and to identify them structurally are described in detail. Two labile intermolecular cross-links were isolated in their reduced forms, one of which was identified by high-resolution mass spectrometry as N∈-(5-amino-5-carboxypentyl)hydroxylysine. The structure of this compound was confirmed by chemical synthesis. The cross-link precursor α-aminoadipic δ-semialdehyde was isolated in its reduced form, ∈-hydroxynorleucine, together with its acid degradation product ∈-chloronorleucine. A relatively stable intermolecular cross-link was isolated and partially characterized by mass spectrometry as an aldol resulting from the reaction of the δ-semialdehyde derived from lysine and hydroxylysine.

scholarly journals The chemistry of the collagen cross-links. The characterization of Fraction C, a possible artifact produced during the reduction of collagen fibres with borohydride

1973 ◽  
Vol 135 (4) ◽  
pp. 657-665 ◽  
Author(s):  
Simon P. Robins ◽  
Allen J. Bailey
Keyword(s):  
Aldol Condensation ◽  
Condensation Product ◽  
Reduced Form ◽  
Borohydride Reduction ◽  
Cross Link ◽  
Collagen Fibres ◽  
Isolation And Identification ◽  
Cross Links

The present paper describes the isolation and identification of a major radioactive component of borotritide-reduced collagen, previously designated Fraction C. The derived structure for the compound confirms that it is identical with the ‘post-histidine’ component described by Tanzer et al. (1973) and given the trivial name histidino-hydroxymerodesmosine. Detailed studies of the effects of acid pH on the formation of Fraction C after borohydride reduction demonstrated the apparent lability of the non-reduced form, thus confirming our previous findings (Bailey & Lister, 1968). Inhibition of the formation of this component by the acid treatment appears to be due to protonation of the histidine imidazole group. Since the only new component formed on reduction of the acid-treated fibres was the reduced aldol condensation product, these results indicate that neither the histidine nor the hydroxylysine residues can be involved in covalent linkage with the aldol condensation product in the native fibre. It is suggested therefore that the proposed non-reduced aldimine form of Fraction C does not exist as an intermolecular cross-link in vivo. Thus the presence of histidino-hydroxymerodesmosine as a tetrafunctional cross-link in reduced collagen fibres is a result of a base-catalysed reaction promoted by the borohydride-reduction procedure and this component must therefore be considered as an artifact.

scholarly journals Application of Molecular Mass Spectrometry for The Structural Characterization of a DNA-Protein Cross-Links

2018 ◽  
Vol 62 (2) ◽  
Author(s):  
Jiawei Gong ◽  
Morwena Jane Solivio ◽  
Edward J Merino ◽  
Julio Alberto Landero Figueroa
Keyword(s):  
Mass Spectrometry ◽  
Small Molecule ◽  
Structural Characterization ◽  
Peptide Sequencing ◽  
Ionization Mass ◽  
Cross Link ◽  
Ms Analysis ◽  
Cross Links ◽  
The Cross

<p>To date, many different analytical methods have been used to investigate the cross-linking reaction mechanism and to obtain the chemical structure of DNA-Protein Cross-links (DPCs). Direct MS analysis of DPCs is challenging because of the ionization properties of DNA and the protein. However, peptide sequencing and mass spectrometry (MS) as analytical techniques are playing increasingly important roles for the structure determination of DPCs model. In our previous study, a novel approach was presented for purification, detection and quantification of DPCs by newly developed inductively coupled plasma mass spectrometry (ICPMS/MS), which allows sub-ppb detection of S and P, key heteroelements in DNA and proteins.</p><p>In this study, we enhanced our previously developed method and it was complemented by the use of molecular MS to allow complete characterization of a DNA-protein cross-link.  First, a small molecule model is utilized to identify the adduct structure that will likely occur in an intact DNA-protein cross-link.  We investigate the thermal stability of DNA-protein cross-links, both in an intact DPC and a small molecule adduct to determine feasibility of digestion/thermal degradationof DNA without the cross-link information being lost.  Thermal degradation was conducted to reduce the cross-linked DNA into a single nucleoside. The remaining protein-nucleoside adduct then was proteolytically digested, generating a peptide-nucleoside adduct. The absence of the phosphate moiety allows for facile structural characterization <em>via</em> electrospray ionization mass spectrometry (ESI-MS).  Additional calculations were done for peptide matching allowing us to determine the cross-link location in the protein, made possible <em>via</em> MS/MS analysis.  Additionally, we show that steric effects play an important role in DPC formation.</p>

scholarly journals The chemistry of the collagen cross-links. Characterization of the products of reduction of skin, tendon and bone with sodium cyanoborohydride

1977 ◽  
Vol 163 (2) ◽  
pp. 339-346 ◽  
Author(s):  
S P Robins ◽  
A J Bailey
Keyword(s):  
Mass Spectrometry ◽  
Time Course ◽  
Chemical Degradation ◽  
Reduced Form ◽  
Intermolecular Bond ◽  
Sodium Cyanoborohydride ◽  
Cross Links

Reduction of tissues with sodium cyanoborohydride at pH7.4 gave results identical with those obtained by KBH4 treatment. On reduction with sodium cyanoborohydride at pH 4.4, however, a previously undetected basic compound was formed and was identified by mass spectrometry and chemical degradation techniques as dihydrohydroxymerodesmosine. Histidino-hydroxymerodesmosine was not present, and further analysis confirmed that reduced aldol, a mojor product of reduction with KBH4 at the lower pH, was also absent. These results, together with an analysis of the time course of the reduction, support previous assertions that histidino-hydroxymerodesmosine is an artifact [robins *Bailey (1973) Biochem. J. 135, 657-665] and suggests that the non-reduced form of hydroxymerodesmosine probably does not constitute a major intermolecular bond in vivo.

scholarly journals A combined flow injection/reversed phase chromatography – high resolution mass spectrometry workflow for accurate absolute lipid quantification with 13C- internal standards

The Analyst ◽  
2021 ◽  
Author(s):  
Harald Schoeny ◽  
Evelyn Rampler ◽  
Yasin El Abiead ◽  
Felina Hildebrand ◽  
Olivia Zach ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Flow Injection ◽  
High Resolution Mass Spectrometry ◽  
Reversed Phase ◽  
Internal Standards ◽  
Lipid Quantification ◽  
High Resolution Mass ◽  
Resolution Mass

We propose a fully automated novel workflow for lipidomics based on flow injection- followed by liquid chromatography high resolution mass spectrometry (FI/LC-HRMS). The workflow combined in-depth characterization of the lipidome...

Sign in / Sign up

Export Citation Format

Share Document