[Activation of prothrombin, modified by maleic anhydride, some properties of N-maleyl-thrombin with free alpha-amino groups].
Conditions for the acylation of bovine prothrombin by maleic anhydride are worked out. The reaction is shown to modify not more than 95% of amino groups. The changes in hydrodynamic and electrophoretic properties testify about structural changes of prothrombin as a result of the modification of free amino groups. The activation of maleyl-prothrombin to maleyl-thrombin took place in 25% sodium citrate only in the presence of thrombin and the Xa factor.  The increase of modified amino groups in prothrombin resulted in the decrease of the activity of generated maleyi-thrombin. The main fraction of maleyl-thrombin with free alpha-amino groups had a sedimentation coefficient of 2.1 S and possessed a residual esterase activity.
D000588:Amines; D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D004789:Enzyme Activation; D004950:Esterases / Q000378:metabolism; D008298:Maleates; D011516:Prothrombin / Q000031:analogs & derivatives* / Q000378:metabolism; D013329:Structure-Activity Relationship; D013917:Thrombin / Q000378:metabolism*
D000588:Amines; D008298:Maleates; D011516:Prothrombin; D004950:Esterases; D013917:Thrombin
Aktivatsiia protrombina, modifitsirovannogo maleinovym angidridom, nekotorye svoĭstva N-maleil-grombina so svobodnymi al'fa aminogruppami