Publications by authors named "Nadia Kulagina"

3 Publications

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12th GCC Closed Forum: critical reagents; oligonucleotides; CoA; method transfer; HRMS; flow cytometry; regulatory findings; stability and immunogenicity.

Bioanalysis 2019 Jun 19;11(12):1129-1138. Epub 2019 Jul 19.

WuXi Apptec, Plainsboro, NJ 08536, USA.

The 12th GCC Closed Forum was held in Philadelphia, PA, USA, on 9 April 2018. Representatives from international bioanalytical Contract Research Organizations were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The issues discussed at the meeting included: critical reagents; oligonucleotides; certificates of analysis; method transfer; high resolution mass spectrometry; flow cytometry; recent regulatory findings and case studies involving stability and nonclinical immunogenicity. Conclusions and consensus from discussions of these topics are included in this article.
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http://dx.doi.org/10.4155/bio-2019-0131DOI Listing
June 2019

Recommendations for classification of commercial LBA kits for biomarkers in drug development from the GCC for bioanalysis.

Bioanalysis 2019 Apr 17;11(7):645-653. Epub 2019 Apr 17.

WuXi Apptec, Plainsboro, NJ, USA.

Over the last decade, the use of biomarker data has become integral to drug development. Biomarkers are not only utilized for internal decision-making by sponsors; they are increasingly utilized to make critical decisions for drug safety and efficacy. As the regulatory agencies are routinely making decisions based on biomarker data, there has been significant scrutiny on the validation of biomarker methods. Contract research organizations regularly use commercially available immunoassay kits to validate biomarker methods. However, adaptation of such kits in a regulated environment presents significant challenges and was one of the key topics discussed during the 12th Global Contract Research Organization Council for Bioanalysis (GCC) meeting. This White Paper reports the GCC members' opinion on the challenges facing the industry and the GCC recommendations on the classification of commercial kits that can be a win-win for commercial kit vendors and end users.
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http://dx.doi.org/10.4155/bio-2019-0072DOI Listing
April 2019

Fragmentation of biotinylated cyclic peptides.

Rapid Commun Mass Spectrom 2004 ;18(12):1277-85

Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.

Electrospray ionization coupled with tandem mass spectrometry (MS/MS) was used to determine the preferred binding site(s) of biotin NHS ester with a series of cyclic peptides with antibiotic properties. The peptides investigated are polymyxins, cyclic peptides produced by Bacillus polymyxa. In spite of the 1:1 stoichiometry used in the labeling reaction, multiple biotin molecules were incorporated into intact polymyxin peptides. Given the amine specificity of the activated biotin and the large number of amino acids with primary amines in the polymyxins, it was not clear by inspection which binding sites were more reactive than others. MS/MS was used to characterize the structure of the biotinylated peptides. MS/MS spectra of cyclic peptides often lead to ambiguous structure determinations due to the potential for multiple ring openings which result in the generation of multiple ion series. The MS/MS spectra of polymyxin peptides are especially difficult to characterize due to the lack of variety in their amino acids; however, the added complexity of the biotin aided the elucidation of the fragmentation pathways. MS/MS spectra of the species with biotin additions were used to rationalize the preferential binding sites of these molecules.
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http://dx.doi.org/10.1002/rcm.1483DOI Listing
July 2004