Isoelectric focusing protein recovery

Figure 4 shows the purity of the expressed CK recovered in fraction 2b. The total recovery of this material can be normalized to 570 gg/1 of culture. The specific activity of the CK refolded from the STET-purified pellet and then purified on FPLC (19.0 U/mg of protein) compares favorably with tissue-isolated CK treated in the same manner (20.3 U/mg of protein). The CK from the two preparations exhibit the same pi values and fractionation pattern on isoelectric focusing gels (data not shown). 

Poly(A)-rich mRNA prepared from rabbit pancreas directed the synthesis of a protein (mol. wt. 5.65 X 10 ), which, using a cell-free protein synthesizing system derived from wheat embryo, appeared to represent the product of o-amylase mRNA cell-free translation.This protein, which was 1500 daltons larger than the purified rabbit pancreas a-amylase, was resolved by isoelectric focusing into discrete species similar to those observed for purified a-amylase. The protein, which on peptide analysis demonstrated considerable identity with the a-amylase, was selectively precipitated by glycogen, but with a much lower recovery than that observed for rabbit on porcine pancreatic a-amylases. 

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