Method of isolating acid-stable, biologically active proteins
OwnerPierre Amiguetinventor
Life of this patent
Estimating the term…
Abstract
A method of isolating cystine rich acid-stable, biologically active proteins comprising the steps of co-precipitation by acidification of said proteins together with at least one acid-sensitive protein; isolation of said proteins from the co-precipitate by its resuspension in aqueous solution and the subsequent recovery of the proteins from the supernatant.
Claims8
A method of isolating biologically active, acid-stable proteins from biological extracts, said acid-stable proteins having a molecular weight not exceeding 15,000 daltons and having a half-cystin content of not less than 5%, consisting of:
- co-precipitating from said extracts said acid-stable proteins to be isolated with acid-sensitive proteins having a molecular weight greater than 15,000 daltons, said co-precipitation being obtained by acidification of said extracts with a strong, protein denaturing acid such that said acid-stable proteins remain undenatured and said acid-sensitive proteins are denatured;
- isolating said undenatured acid-stable proteins from the co-precipitate thus formed by resuspending said co-precipitate in an aqueous solution, separating all insoluble material and recovering said undenatured acid-stable proteins from the aqueous phase, the residual contaminants thereof consist of nonproteinic material only in an amount of less than 10% by weight.
A method of isolating biologically active, acid-stable proteins from biological extracts comprising acid-stable proteins and acid-sensitive proteins, comprising
- acidifying an extract comprising acid-sensitive proteins having a molecular weight greater than 15,000 daltons and acid-stable proteins selected from the group consisting of calcitonin, human transforming growth factor, insulin, Kazal Inhibitor of trypsin, aprotinin, Inhibitor of colostral trypsin, Bowman-Birk Inhibitor, proinsulin, neurophysin, ribonuclease, lysozyme, and mixtures of any of the foregoing, with a strong acid comprising trichloroacetic acid, such that a coagulation is obtained comprising said acid-stable proteins physically entrapped in said acid-sensitive proteins, said acid-stable proteins being undenatured and said acid-sensitive proteins being denatured,
- isolating said acid-stable proteins from said coagulation by resuspending said coagulation in an aqueous phase,
- separating all insoluble material and recovering said acid-stable proteins from the aqueous phase, such that the residual contaminants thereof consist of nonproteinic material only in an amount of less than 10% by weight.
Dependencies are inferred from the claim text.