Strategies Based upon Molecular Weight Measurements

Strategies Based upon Molecular Weight Measurements 

Molecular Weights of Peptides and Proteins. Traditionally, organic mass spec-troscopists have utilized peaks corresponding to monoisotopic ion species (containing only H, N, 0, etc.) to determine molecular or fragment masses (Table 10.1). While their relative abundances are low, the contribution to the molecular-ion mass from one or several and isotopes increases for peptides 

FIGURE 10.1 Molecular weight strategies for protein and peptide analysis by time-of-flight mass spectrometry. 

TABLE lO.I encountered Isotopic abundances and masses of elements in peptides and other biological molecules.  

Element Nominal mass Exact mass Percent abundance Average mass 

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Strategies Based upon Molecular Weight Measurements... 

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