Characterization of glandless cottonseed protein /
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1988.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | A Study of the distribution of proteins in defatted glandless cottonseed meal showed that the albumin fraction (nonstorage protein) and the globulin fraction (storage protein) constituted 25 and 58% of the total protein, respectively. The prolamine and glutelin fractions; and the insoluble residual nitrogen constituted approximately 1.8, 5.5, and 7.5% of the total protein, respectively. In the absence of 2-mercaptoethanol (2- ME), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the albumin fraction contained two prominent bands with molecular weights (MW) of 20,000 and 15,000, and the globulin fraction contained eight bands with MW ranging from 100,000 to 18,000. The albumin fraction contained high percentages of lysine, cystine, and methionine. Nonstorage protein was fractionated by gel filtration into six protein fractions (A to F) with Stokes' radii of >61.0, 41.1, 28.9, 20.7, 11.7, and <11.7 A, respectively. Fraction A-F constituted about 12, 31, 17, 22, 11, and 7% of the nonstorage protein, respectively. Each fraction contained a high level of lysine. Gel electrophoresis showed that fractions A-E were quite heterogeneous. In the presence of 2-ME, SDS-PAGE showed that all six fractions showed one major band with MW less than 15,000. All protein bands reacted negatively to periodic acid Schiff stain. Storage protein was fractionated by gel filtration chromatography into five fractions (I to V) with Stokes' radii of >61.0, 56.2, 48.5, 22.1, and <16.4 Å, respectively. Fractions l-V constituted about 4, 16, 10, 58, and 12% of storage protein, respectively. Fraction V contained a large amount of lysine and was homogeneous as determined by gel electrophoresis at pH 8.3. SDS-PAGE showed that fractions I, II, and III had similar polypeptide profiles. Almost every polypeptide reacted positively to periodic acid Schiff stain. Acalin A, acalin B, and fraction S9 were isolated in homogeneous forms. Their Stokes; radii were found to be 34.6, 47.5, and <16.4 Å, respectively. SDS-PAGE showed that acalin A and acalin B contained eight subunits each with MW between 67,000 and 18,000, and fraction S9 had two major subunits with MW of 58,000 and 52,000. The secondary structure of proteins in their native states consisted predominately of an aperiodic structure. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Food Science and Technology." |
| Physical Description: | xiii, 95 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 89-94). |