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Ammonium Sulfate Selectively Extracts Invertase Activity from a Mixture of Precipitated Yeast Proteins
Author(s) -
Cook Rachel M,
Gontkovic Anna J,
Lawrence Jim,
Timerman Anthony
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.752.4
Subject(s) - invertase , ammonium sulfate , chemistry , chromatography , yeast , extraction (chemistry) , pellet , ammonium , biochemistry , enzyme , ethanol , biology , organic chemistry , zoology
The purpose of this work was to improve the first step in a sequence of Chemistry 365 (Biochemistry) lab exercises in which students purify the enzyme invertase from a yeast extract that contains many other different proteins. The essence of the first step in this protein purification exercise is to precipitate many different proteins using aqueous solutions of ethanol and then selectively extract soluble proteins from the pellet in a buffer composed of 10 mM sodium phosphate at pH 7.0. Our results show that the addition of ammonium sulfate to the extraction buffer greatly reduces the total mass of proteins extracted from the pellet with a minimal loss of extracted invertase activity. SDS‐PAGE analysis of the final fraction prepared by this modified method reveals a sample with a fewer number of contaminating protein bands than that observed in a commercial sample of “pure‐invertase” purchased from Sigma Chemical Company.