Isolation and characterization of autoantibodies against human cystatin C.
Hereditary cystatin C amyloid angiopathy (HCCAA) is a severe neurodegenerative disorder related to the point mutation in cystatin C gene resulting in human cystatin C (hCC) L68Q variant. One of the potential immunotherapeutic approaches to HCCAA treatment is based on naturally occurring antibodies against cystatin C. A recent growing interest in autoantibodies, especially in the context of neurodegenerative diseases, emerges from their potential use as valuable diagnostic markers and for controlling protein aggregation. In this work, we present characteristics of natural anti-hCC antibodies isolated from the IgG fraction of human serum by affinity chromatography. The electrophoresis (1-D and 2-D) results demonstrated that the isolated NAbs are a polyclonal mixture, but their electrophoretic properties did not allow to classify the new autoantibodies to any particular type of IgG. The Fc-glycan status of the studied autoantibodies was assessed using mass spectrometry analysis. For the isolated NAbs, the epitopic fragments in hCC sequence were identified by MS-assisted proteolytic excision of the immune complex and compared with the ones predicted theoretically. The knowledge of hCC fragments binding to NAbs and other ligands may contribute to the search for new diagnostic methods for amyloidosis of different types and the search for their treatment.
Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland.
Martyna
M
Prądzińska
Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland.
Izabela
I
Behrendt
Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland.
Marta
M
Spodzieja
Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland.
Aleksandra S
AS
Kołodziejczyk
Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland.
Sylwia
S
Rodziewicz-Motowidło
Faculty of Chemistry, Department of Biomedical Chemistry, University of Gdansk, Wita Stwosza 63, 80-952, Gdansk, Poland.
Aneta
A
Szymańska
Division of Chemistry I, Head Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheelesvag 2, SE 17177, Stockholm, Sweden.
Susanna L
SL
Lundström
Division of Chemistry I, Head Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheelesvag 2, SE 17177, Stockholm, Sweden.
Roman A
RA
Zubarev
Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kładki 24, 80-822, Gdansk, Poland.
Katarzyna
K
Macur
Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kładki 24, 80-822, Gdansk, Poland. pczaplewska@gmail.com.
Paulina
0000-0002-6469-6014
P
Czaplewska
D019943:Amino Acid Substitution; D001323:Autoantibodies / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D002846:Chromatography, Affinity / Q000379:methods*; D055316:Cystatin C / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D017354:Point Mutation
D001323:Autoantibodies; C525030:CST3 protein, human; D055316:Cystatin C; D007074:Immunoglobulin G
Autoantibodies; Epitope; Human cystatin C; Mass spectrometry