Different NH2-terminal form with 12 additional residues of alpha 2-plasmin inhibitor from human plasma and culture media of Hep G2 cells.
alpha 2-Plasmin inhibitor (alpha 2PI) was purified from plasma or from the culture media of Hep G2 cells by one-step immunoaffinity chromatography procedure. Majority of alpha 2PI purified from plasma was the previously recognized plasma alpha 2PI with NH2-terminal Asn (Asn-alpha 2PI), whereas majority of alpha 2PI purified from the culture media was retaining the "pro" peptide of 12 amino acids with NH2-terminal Met (Met-alpha 2PI). When Hep G2 cells were cultured in serum-free media, the alpha 2PI secreted to the media was totally in a form of Met-alpha 2PI. Incubation of Met-alpha 2PI with human plasma induced the complete conversion of Met-alpha 2PI to Asn-alpha 2PI. The results indicate that alpha 2PI is synthesized and secreted from liver cells as Met-alpha 2PI and Met-alpha 2PI is converted to Asn-alpha 2PI by proteolytic cleavage in plasma during the circulation.
Koyama
T
T
First Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Koike
Y
Y
Toyota
S
S
Miyagi
F
F
Suzuki
N
N
Aoki
N
N
D000595:Amino Acid Sequence; D002460:Cell Line; D002846:Chromatography, Affinity; D016895:Culture Media, Serum-Free; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D014407:Tumor Cells, Cultured; D000979:alpha-2-Antiplasmin / Q000737:chemistry* / Q000302:isolation & purification
D016895:Culture Media, Serum-Free; D000979:alpha-2-Antiplasmin