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This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Allhorn, M. Articles by Åkerström, B. Search for Related Content PubMed PubMed Citation Articles by Allhorn, M. Articles by Åkerström, B. Related Collections Red Cells Plenary Papers Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  Blood, 15 March 2002, Vol. 99, No. 6, pp. 1894-1901 PLENARY PAPER Processing of the lipocalin 1-microglobulin by hemoglobin induces heme-binding and heme-degradation properties Maria Allhorn, Tord Berggård, Jonas Nordberg, Martin L. Olsson, and Bo Åkerström From the Department of Cell and Molecular Biology, Lund University, and Department of Transfusion Medicine, Blood Center, University Hospital, Lund, Sweden. 1-Microglobulin is a 26-kd protein, widespread in plasma and tissues and well-conserved among vertebrates. 1-Microglobulin belongs to the lipocalins, a protein superfamily with highly conserved 3-dimensional structures, forming an internal ligand binding pocket. The protein, isolated from urine, has a heterogeneous yellow-brown chromophore bound covalently to amino acid side groups around the entrance of the lipocalin pocket. 1-Microglobulin is found in blood both in free form and complex-bound to immunoglobulin A (IgA) via a half-cystine residue at position 34. It is shown here that an 1-microglobulin species, which we name t-1-microglobulin (t = truncated), with a free Cys34 thiol group, lacking its C-terminal tetrapeptide, LIPR, and with a more polar environment around the entrance of the lipocalin pocket, is released from IgA-1-microglobulin as well as from free 1-microglobulin when exposed to the cytosolic side of erythrocyte membranes or to purified oxyhemoglobin. The processed t-1-microglobulin binds heme and the 1-microglobulin-heme complex shows a time-dependent spectral rearrangement, suggestive of degradation of heme concomitantly with formation of a heterogeneous chromophore associated with the protein. The processed t-1-microglobulin is found in normal and pathologic human urine, indicating that the cleavage process occurs in vivo. The results suggest that 1-microglobulin is involved in extracellular heme catabolism. © 2002 by The American Society of Hematology.   CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? This article has been cited by other articles: L. Andersson, B. Haraldsson, C. Johansson, and L. Barregard Methodological issues on the use of urinary alpha-1-microglobuline in epidemiological studies Nephrol. Dial. Transplant., April 1, 2008; 23(4): 1252 - 1256. [Abstract] [Full Text] [PDF] B. Akerstrom, G. J. Maghzal, C. C. Winterbourn, and A. J. Kettle The Lipocalin {alpha}1-Microglobulin Has Radical Scavenging Activity J. Biol. Chem., October 26, 2007; 282(43): 31493 - 31503. [Abstract] [Full Text] [PDF] S. Fagoonee, J. Gburek, E. Hirsch, S. Marro, S. K. Moestrup, J. M. Laurberg, E. I. Christensen, L. Silengo, F. Altruda, and E. Tolosano Plasma Protein Haptoglobin Modulates Renal Iron Loading Am. J. Pathol., April 1, 2005; 166(4): 973 - 983. [Abstract] [Full Text] [PDF] A. Sala, M. Campagnoli, E. Perani, A. Romano, S. Labo, E. Monzani, L. Minchiotti, and M. Galliano Human {alpha}-1-Microglobulin Is Covalently Bound to Kynurenine-derived Chromophores J. Biol. Chem., December 3, 2004; 279(49): 51033 - 51041. [Abstract] [Full Text] [PDF]

	Copyright © 2002 by American Society of Hematology         Online ISSN: 1528-0020