Search by BoMiProt ID - Bomi99

Primary Information

BoMiProt ID Bomi99
Protein Name AMBP
Organism Bos taurus
Uniprot IdP00978
Milk FractionWhey
Ref Sequence Id NP_776414.1
Aminoacid Length 352
Molecular Weight 39235
Fasta Sequence
Gene Name AMBP
Gene Id 280996
Protein Existence Status Reviewed: Experimental evidence at protein level

Secondary Information

Presence in other biological fluids/tissue/cells Liver, blood, kidney, developing gut, vessel epithelia of the umbilical cord, pancreas
Protein Function codes for a polypeptide that gives rise to two different secreted proteins - α1-microglobulin and bikunin. Protein AMBP is a precursor of a heme-binding protein that counteracts the damaging effects of free hemoglobin, which may be related to the presence of free hemoglobin in CSF.
Biochemical Properties α1-microglobulin binds a chromophore formed during heme-binding and degradation; bikunin is a proteinase inhibitor of the inter-a-inhibitor family
Significance in milk source of α trypsin inhibitors in milk;
PTMs Cleavage on pair of basic residues, Disulfide bond formation, Glycosylation at Asn
Site(s) of PTM(s)

N-glycosylation, O-glycosylation,
Predicted Disorder Regions 187-223
DisProt Annotation
TM Helix Prediction No TM helices
Significance of PTMs 3-hydroxykynurenine, an oxidized tryptophan metabolite that is common in biological fluids, reacts with Cys-53, Lys-111, Lys-137, and Lys-149 to form heterogeneous polycyclic chromophores including hydroxanthommatin. The reaction by alpha-1-microglobulin is autocatalytic. The chromophore can react with accessible cysteines forming non-reducible thioether cross-links with other molecules of alpha-1-microglobulin or with other proteins such as Ig alpha-1 chain C region. Heavy chains are interlinked with bikunin via a chondroitin 4-sulfate bridge to the their C-terminal aspartate.
Bibliography 1. Sánchez, D., Martínez, S., Lindqvist, A., Åkerström, B., & Falkenberg, C. (2002). Expression of the AMBP gene transcript and its two protein products, α1-microglobulin and bikunin, in mouse embryogenesis. Mechanisms of Development, 117(1–2), 293–298.
2. Allhorn, M., Berggård, T., Nordberg, J., Olsson, M. L., & Akerström, B. (2002). Processing of the lipocalin alpha(1)-microglobulin by hemoglobin induces heme-binding and heme-degradation properties. Blood, 99(6), 1894–1901.
3. Lindqvist, A., Rouet, P., Salier, J. P., & Akerström, B. (1999). The alpha1-microglobulin/bikunin gene: characterization in mouse and evolution. Gene, 234(2), 329–336. 4.van den Berg CB, Duvekot JJ, Güzel C, Hansson SR, de Leeuw TG, Steegers EA, Versendaal J, Luider TM, Stoop MP. Elevated levels of protein AMBP in cerebrospinal fluid of women with preeclampsia compared to normotensive pregnant women. Proteomics Clin Appl. 2017 Jan;11(1-2). doi: 10.1002/prca.201600082. Epub 2016 Oct 24. PMID: 27615121.