The distribution of glucuronic and @entity16369 within the chains of anticoagulantly active and inactive beef lung heparin was investigated. A fraction with an average molecular weight of 19,500 was isolated from the heterodisperse mixture and then separated into active and inactive components by affinity chromatography. Each sample was linked through its reducing terminus to @entity6114 , reduced with @entity8951 , and bound covalently to Sepharose via an azo bridge. The bound reduced heparin was treated with a limited amount of @entity12005 and the degraded fragments were removed. The sections of the chain contiguous with the original reducing terminus were then detached from the insoluble matrix by reaction with @entity6857 . The recovered polysaccharide was fractionated according to size on Sephadex G-200 and the amount of each @entity13275 in the individual fractions was determined. Inactive heparin showed a constant percentage of @entity8686 in all fragments, i.e. about 8.9% of the total @entity13275 . With active heparin the percentage of @entity8686 increased with the distance from the reducing terminus of the polysaccharide chain, ranging from 9.5 to 20% of the uronic acids. These results suggest that the biosynthesis of active heparin involves unique reactions or specific processing of the macromolecule.

Distribution of glucuronic and XXXX units in heparin chains.

@entity13275 :: ('CHEBI:27252', 'Chemical') :: ['uronic acid'] @entity8951 :: ('MESH:C025364', 'Chemical') :: ['sodium borotritide'] @entity16369 :: ('MESH:D007067', 'Chemical') :: ['iduronic acid'] @entity8686 :: ('MESH:D020723', 'Chemical') :: ['glucuronic acid'] @entity6857 :: ('MESH:D004227', 'Chemical') :: ['sodium dithionite'] @entity12005 :: ('CHEBI:25567', 'Chemical') :: ['HNO2'] @entity6114 :: ('MESH:D014439', 'Chemical') :: ['tyramine']
@entity16369 :: (MESH:D007067,Chemical) :: ['iduronic acid']
