alpha-1 microglobulin; alpha-1 antitrypsin light chain; protein HC; bikunin (a lipocalin, AMBP, HCP, ITIL)

Function

• found as free monomer & in complexes with IgA & albumin
• binds porphyrins
• inter-alpha-trypsin inhibitor
• inhibits trypsin, plasmin, & lysosomal granulocytic elastase

Structure

• inter-alpha-trypsin inhibitors are assembled from 1 or 2 heavy chains & one light chain, alpha-1 microglobulin (bikunin); heavy chains are linked to bikunin via chondroitin 4-sulfate esterified to the alpha-carboxyl of C-terminal aspartate after propeptide cleavage

Expression

• expressed by the liver & secreted into plasma
• found in many body fluids including:
  • plasma
  • urine
  • cerebrospinal fluid
  • amniotic fluid

More general terms

• protein subunit
• alpha 1 globulin
• microglobulin
• lipocalin

Additional terms

• alpha-1-microglobulin in vaginal fluid

Component of

• inter alpha trypsin inhibitor (inter-alpha-inhibitor, I-alpha-I)

Database

• UniProt: http://www.uniprot.org/uniprot/P02760.html
• OMIM: https://mirror.omim.org/entry/176870
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=259