Studies On The New Process Of Aprotinin From Bovine Lungs

Aprotinin is a natural,broad-spectrum,nonspecific serine proteinaseinhibitor consisting of fifty-eight amino acids residue arranged in a singlepolypeptide chain, cross-linked by three disulfide bridges and having amolecular mass of 6512 Daltons. It is isolated from bovine lung tissue. Itdoesn't work by p.o, and is usually used by iv or put in pump prime. After iv,aprotinin will distribute immediately into the whole extracellular fluid and itshalf-life time is about 2 hours. Aprotinin can't pass through the normalblood-brain barrier and only a few parts of it passes through the placentalbarrier. Aprotinin is metabolized in the kidney and excreted from the urine. Aprotinin acts in a number of interrelated ways to provide anantifibrinolytic effect, inhibit contact activation, reduce platelet dysfunctionand attenuate the inflammatory response. For coagulation and fibrinolysissystem, aprotinin inhibits the activity of several proteolytic enzymes such asplasmin, thrombin, trypsin, kallikrein and blood coagulation factors â…£-â…«.Because aprotinin may provide actions such as an antifibrinolytic effect,protection from ischemia-reperfusion injury, reduction of platelet dysfunctionand attenuation of inflammatory response to CPB, it has been widely used inpatients with an increased risk of bleeding, especially in cardiac surgery withCPB, major orthopedic surgery, organ transplantion, repeat surgery and otherfields. In many surgery, aprotinin can significantly reduce the postoperativeblood loss(40%-80%) and the requirement for allogenic blood transfusions(70%-100%).Overall, aprotinin is a safe, effective medicine, and will have a wonderfulfuture in clinical use.â… .The Extraction of Aprotinin from Bovine LungsWe Extract Aprotinin from 1000Kg Bovine Lungs by 0.5%H2SO4 andgain about 2000 litres aprotinin solution. Then we ultrafilter the aprotininsolution with 30K ultrafilters. Then we condense the solution with 3Kultrafilters until it's vol. is 100 litres.â…¡.The Purification of AprotininWe add 50% TCA to the aprotinin solution until it's concentration is 2.5%and get rid of some impurity proteins by filtration. Then we adjust the solutionpH4.5 and add 1/10 the volume of the solution 200mM NaAc-HAc buffer tothe solution. And purify the aprotinin through the SP Sepharose XL andexclude the aprotinin from the resin by 1.0mol/LNaCl to gain pure aprotininsolution.At last we get rid of the lipopolysaccharid(LPS) by milipore systemwhich can head off large molecular impurity.After analysis:We gain 200million KIU aprotinin from 1000Kg bovine lungs,about 30g.