Week 10 HW: Imaging and Measurement

Waters Lab Part I

  1. 28006.60Da

  2. z=32 based on consecutive m/z’s (875.4421, 848.9162); MW = 27982Da; Accuracy = 99.9%

  3. No, its amplitude above background could mean it’s not reliably distinguished from background noise.

Waters Lab Part II

  1. When a protein unfolds, several more ionizable sites on the polypeptide are exposed. As such, the denatured protein will exhibit several more m/z peaKs, and typically at higher m/z values than the native protein conformation.

  2. The charge state is +0 based on the maximal abundance of the protein.

Waters Lab Part III

  1. MVSKGEELFTG VVPILVELDG DVNGHKFSVS GEGEGDATYG K**LTL**KFICTT GK**LPVPWPTL VTTLTYGVQC FSRYPDHMKQ HDFFKSAMPE GYVQERTIFF KDDGNYKTRA EVKFEGDTLV NRIEL**KGIDF KEDGNILGHK LEYNYNSHNV YIMADKQKNG IKVNFKIRHN IEDGSVQLAD HYQQNTPIGD GPVL**LPDNHY LSTQSALSKD PNEKRDHMVL LEFVTAAGIT LGMDELYK**LE HHHHHH

20 K residues; 22 L residues

  1. Trypsin digestion yields 19 fragments

  2. 21 peaks

  3. There are more peaks in the chromatogram than expected

Waters Lab Part IV

7FU Decamer – Blue 3.4MDa peak 8FU Didecamer – Pink 8.33MDa peak 8FU 3-Decamer – Pink 12.67MDa peak 8FU 4-Decamer – Blue 16MDa peak cluster

Waters Lab Part V

Theoretical Observed/measured on the Intact LC-MS: 28006 PPM Mass Error: 857ppm Molecular weight (kDa): 28