Affordable Access

Publisher Website

Posttranslational modifications in human plasma MBL and human recombinant MBL

Authors
Journal
Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics
1570-9639
Publisher
Elsevier
Publication Date
Volume
1774
Issue
3
Identifiers
DOI: 10.1016/j.bbapap.2006.12.008
Keywords
  • Hydroxylysine
  • Hydroxyproline
  • Dehydroalanine From Cysteine
  • Collectin
  • Mass Spectrometry
  • Plasma Protein
Disciplines
  • Biology

Abstract

Abstract Mannan-binding lectin (MBL) is a complex serum protein that plays an important role in innate immunity. In addition to assuming several different oligomeric forms, the polypeptide itself is highly heterogeneous. This heterogeneity is due to post-translational modifications, which help to stabilize the intact protein in its active conformation. For the first time, positions and occupation frequency of partial hydroxylations and partial glycosylations are reported in MBL. Hydroxylation and glycosylation patterns of both recombinant and plasma derived MBL were determined, using a combination of mass spectrometry on reduced MBL and on enzyme cleaved MBL. Variations in the degree of hydroxylation and glycosylation seem to be an indigenous characteristic of collectins. In addition to these already known modifications, a new post-translational modification was identified. Cys 216 (and occasionally also Cys 202) was modified in trace amounts to dehydroalanine, as detected by a 34 Da mass loss. This impairs the formation of a disulphide bond in the carbohydrate recognition domain. The dehydroalanine was identified in similar small amounts in both recombinant and plasma-derived MBL.

There are no comments yet on this publication. Be the first to share your thoughts.