Detection of a gamma-carboxy-glutamate as novel post-translational modification of human transthyretin.

During analysis of the proteome in the cerebrospinal fluid (CSF) of the Caucasian form of moyamoya disease (MMD), a novel post-translational modification of human transthyretin was observed. Two-dimensional electrophoresis and subsequent peptide sequencing with ESI-MS/MS were performed to discover the gamma-carboxylation of the Glu-42 (Gla-42).