Intact Mass Analysis

Protein intact mass analysis offers precise measurement of intact protein mass in native or denatured condition. Our platform uses the Orbitrap Exploris with Biopharma option for maximum detection and quantitation of all mass components of target protein.

We have optimized protein intact mass protocols starting from sample preparations to mass spectrometry scan settings to fit different kinds of proteins. The following is an example of measuring protein intact mass of a monoclonal antibody in a buffer containing high salt and detergent.

Figure 1: MS1 Spectra of mAb

In the MS1 scan of the protein, a “charge envelope” pattern is produced. Typically there are multiple high-abundance m/z peaks, with the highest peak being the middle.

Figure 2: Deconvoluted Spectra of mAb

BioPharma Finder 5.1 analyzes the MS1 spectra and chromatogram by deconvoluting it into mass peaks. The most abundant mass of the protein is shown as a dominant main peak.

Intact Mass Experimental Procedure:

1. Sample preparation: Sample is prepared in an appropriate buffer
2. Sample desalting: Remove salt, detergent and other chemicals that interfere with intact mass analysis
3. Intact mass analysis by Orbitrap Exploris: Optimal scan settings are used to obtain the best MS spectra
4. Data Analysis: The MS spectra is deconvoluted & analyzed in BioPharma Finder 5.1 to determine the molecular weight and other component masses

Data Report covers the following:

1. MS Spectra: Protein fingerprint showing the peaks and charge states at various m/z
2. Deconvoluted Spectra: Main peak & mass of the protein, along with smaller peaks of minor components
3. Component-level data including abundance, intensity, confidence, and number of charge states
4. Charge state-level data