Microfibril-associated protein 4 is present in lung washings and binds to the collagen region of lung surfactant protein D

Mette Lausen, Nicholas Lynch, Anders Schlosser, Ida Tornøe, Susanne Gjørup Sækmose, Børge Teisner, Antony C. Willis, Erika Crouch, Wilhelm Schwaeble, Uffe Holmskov

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

We have purified a glycoprotein from bovine lung washings using affinity chromatography on a maltose-affinity column. On SDS-polyacrylamide gel electrophoresis the protein showed a molecular mass of 36 kda in the reduced state and 66 kda in the unreduced state. On gel permeation chromatography the apparent molecular mass was 250 kda. N-terminal sequencing showed homology to the human matrix protein microfibril-associated protein (hMFAP4), and the glycoprotein was designated bovine MFAP4 (bMFAP4). Lung surfactant protein D (SP-D) was also purified from lung washings, and calcium-dependent binding was demonstrated between bMFAP4 and SP-D. hMFAP4 was cloned, and recombinant hMFAP4 showed the same binding pattern to SP-D as bMFAP4. No binding was seen to recombinant SP-D composed of the neck region and carbohydrate recognition domain of SP-D, indicating that the interaction between MFAP4 and SP-D is mediated via the collagen region of SP-D. MFAP4 also showed calcium-dependent binding to mannan, which was partially inhibited by maltose. Our findings indicate that MFAP4 has two binding specificities, one for collagen and one for carbohydrate, and we suggest that MFAP4 may fix the collectins in the extracellular compartment during inflammation.

Original languageEnglish
Pages (from-to)32234-32240
Number of pages7
JournalJournal of Biological Chemistry
Volume274
Issue number45
DOIs
StatePublished - Nov 5 1999

Fingerprint

Dive into the research topics of 'Microfibril-associated protein 4 is present in lung washings and binds to the collagen region of lung surfactant protein D'. Together they form a unique fingerprint.

Cite this