Summary
At least four molecular forms of plasminogen are known. Two of those forms have glutamic
acid at their amino-terminal end, and are designated as glu-plasminogen. The other
two have lysine, methionine and/or valine as amino-terminal amino acid and are collectively
designated as lys-plasminogen. Two subforms (I and II) each of glu- and lys-plasminogen
exist. The I-forms are glycosylated at asn-288 and thr-345, whereas the II-forms are
only glycosylated at thr-345. In a previous publication (Thromb Haemostas 1984; 52:
347-349) we have described the separation of the I- and II-forms of plasminogen in
lysine-Sepharose in phosphate buffers. Now we have combined those findings with the
differential affinity of glu- and lys-plasminogen for aminohexyl-Sepharose through
their aminohexyl-sites, recently described by Christensen (Biochem J 1984; 223: 431-421).
Acid/urea electrophoresis, end-group determination and carbohydrate analysis show
that the combination of affinity chromatography on lysine-Sepharose in phosphate buffers,
and on aminohexyl-Sepharose provides an efficient procedure to separate the four molecular
forms of plasminogen.
Keywords
Plasminogen - Affinity chromatography - Lysine-Sepharose - Aminohexyl-Sepharose
