Evaluation of the possible proteomic application of trypsin from Streptomyces griseus
| Authors | |
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| Year of publication | 2008 |
| Type | Article in Periodical |
| Magazine / Source | Analytical Biochemistry |
| MU Faculty or unit | |
| Citation | |
| Field | Biochemistry |
| Keywords | In gel digestion; MALDI TOF MS; Peptide mass fingerprinting; Protein modification; Streptomyces griseus; Trypsin |
| Description | In this work, trypsin from Streptomyces griseus (SGT) was purified to homogeneity and evaluated in in-gel digestion of protein standards followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses of the digests. The number of produced and matching tryptic peptides was higher than in the case of commonly used bovine trypsin and allowed us to obtain higher identification scores in database searches. Interestingly, SGT was found to also generate nonspecific peptides, a partial F-X, Y-X, and W-X cleavage specificity. To suppress autolysis, either arginine or arginine plus lysine residues in SGT were modified by chemical reagents. In consequence, the autolytic pattern of SGT was reduced significantly, but specific activity dropped dramatically. As demonstrated by relative quantification, SGT is more stable at 37 degs than is its bovine counterpart. We conclude that SGT represents a convenient alternative for proteomic applications involving protein digestion. Moreover, parallel digestions of sample aliquots by SGT and BT provide the possibility of combining partially different results (unique matching peptides) to improve protein identification. |
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