Functional antithrombin-III variant (41 Pro----Leu) identified by liquid secondary ion mass spectrometry.
A genetic variant of antithrombin with impaired heparin cofactor activity was identified in 4 members of a French family. Both the variant and normal antithrombin component were purified by affinity chromatography on heparin Sepharose. Reverse phase peptide mapping revealed a single altered peak when tryptic digests of both antithrombins were compared. After further purification of the aberrant peptide, amino acid analysis indicated a substitution of 41 Leu----Pro (antithrombin Basel). This result was confirmed by liquid secondary ion mass spectrometry which gave a measured mass of 816.4655 Da for the new peptide compared to a calculated mass of 800.3579 Da for the normal peptide and 816.4579 for the Leu----Pro substitution.
Brennan
S O
SO
Department of Clinical Biochemistry, Christchurch Hospital, New Zealand.
Borg
J Y
JY
Shaw
G J
GJ
Caen
J
J
George
P M
PM
D000328:Adult; D000596:Amino Acids / Q000032:analysis; D000990:Antithrombin III / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D010375:Pedigree; D013927:Thrombosis / Q000097:blood / Q000235:genetics
D000596:Amino Acids; C047699:antithrombin III Basel; D000990:Antithrombin III