Carbonic Anhydrase I Is Recognized by an SOD1 Antibody upon Biotinylation of Human Spinal Cord Extracts

International Journal of Molecular Sciences

Jian Liu¹  Armin Akhavan²  Mengde Lu¹  Arie Gruzman³  Vishwanath R. Lingappa³  Jiyan An⁴ 

[1]Department of Neuroscience, California Pacific Medical Center Research Institute, 475 Brannan Street, San Francisco, CA 94107, USA

[2] E-Mail:

[3]Department of Cancer Research, California Pacific Medical Center Research Institute, 475 Brannan Street, San Francisco, CA 94107, USA

[4] E-Mail:

[5]Department of Bioconformatics, California Pacific Medical Center Research Institute, 475 Brannan Street, San Francisco, CA 94107, USA

[6] E-Mails:

[7]Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA

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关键词: mass spectrometry;    proteomics;    biotinylation;    SOD1;    ALS;    carbonic anhydrase I;   

DOI  :  10.3390/ijms11104051

来源: mdpi

【 摘 要 】

We recently reported the presence of a novel 32 kDa protein immunoreactive to a copper, zinc superoxide dismutase (SOD1) antibody within the spinal cord of patients with amyotrophic lateral sclerosis (ALS). This unique protein species was generated by biotinylation of spinal cord tissue extracts to detect conformational changes of SOD1 specific to ALS patients. To further characterize this protein, we enriched the protein by column chromatography and determined its protein identity by mass spectrometry. The protein that gave rise to the 32 kDa species upon biotinylation was identified as carbonic anhydrase I (CA I). Biotinylation of CA I from ALS spinal cord resulted in the generation of a novel epitope recognized by the SOD1 antibody. This epitope could also be generated by biotinylation of extracts from cultured cells expressing human CA I. Peptide competition assays identified the amino acid sequence in carbonic anhydrase I responsible for binding the SOD1 antibody. We conclude that chemical modifications used to identify pathogenic protein conformations can lead to the identification of unanticipated proteins that may participate in disease pathogenesis.

【 授权许可】

CC BY   
© 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.