| 摘要 |
PURPOSE:To increase the activity ratio of a plasminogen activator precursor, by cultivating a human kidney-derived established cell transformed with a vector containing a DNA sequence capable of coding the plasminogen activator in a culture medium containing a neutral amino acid. CONSTITUTION:A human kidney-derived established cells transformed by using a vector containing a DNA sequence capable of coding a plasminogen activator precursor are cultivated in a culture medium containing at least a neutral amino acid. The aimed plasminogen precursor is recovered from the culture medium by using a means, e.g. centrifugation, concentration under reduced pressure, salting out, fractionation, etc. The vector for expressing the precursor is constituted of, e.g. enhancer, initial promoter, etc., derived from SV-40 as an expression system gene. Glycine, alanine, leucine, etc., are cited as the neutral amino acid contained in the culture medium. |
