| 摘要 |
<p>A process for the preparation of a derivative of an in vivo fibrinolytic enzyme, which enzyme, when ststemically administered in not more than five hours to a rabbit with a radioactively labelled clot localised in its inferior vena cava, will raise the blood radioactivity level to at least twice that of the background level in six hours from beginning the administration without causing death of the animal, and wherein the catalytic site essential for fibrinolytic activity is blocked by a group which is removable by hydrolysis such that the pseudo-first order rate constant for hydrolysis of the derivative is in the range 10-6 sec-1 to 10-3 sec1 in isotonic aqueous medis at pH 7.4 at 37.degree.C which comprises (a) reacting an in vivo fibrinolytic enzyme with a blocking agent: AB wherein A is a group which is selective for the catalytic site essential for fibrinolytic activity and which is capable of transferring from the group B to the catalytic site and B is a group which facilitates the attachment of A to the enzyme; or (b) reacting an in vivo fibrinolytic enzyme with a compound: EF wherein E is a locating group which is selective for the catalytic site and F is a group which is capable of transferring from the locating group to the active site. The derivative of the in vivo fibrinolytic enzyme is novel and is useful in the treatment of venous thrombosis.</p> |
