Synapt hdms esi q tof mass spectrometer

The purity from samples of each puri cation step was checked by tricine-SDS-PAGE as described by Schagger and Von Jagow [23] (link). Low-range molecular weight standards (14.4-97.4 kDa) were employed for apparent molecular mass estimation of ShTI (GelAnalyzer 2010a software) under nonreducing conditions. Protein bands were revealed by staining the gel with 0.1% (m/v) Coomassie Brilliant Blue R-250 and distaining with distilled water, methanol, and acetic acid (5:4:1-v/v/v).
The average molecular mass of ShTI was determined using electrospray ionization-mass spectrometry (ESI-MS). Pure samples of ShTI (60 ρ.Mol.µL - 1 ; prepared in 50% (v/v) acetonitrile containing 0.2% formic acid (v/v)) were applied to a nanoelectrospray source coupled to a Synapt HDMS ESI-Q-ToF mass spectrometer (Waters Corp., Milford, MA, USA) using a Hamilton syringe. The instrument was calibrated with phosphoric acid and operated in positive-ion mode under 3.5 kV capillary voltage at 363 K source temperature. Mass spectra were acquired by scanning at m/z from 1000 to 2100 and at 1 scan•s - 1 . Mass Lynx 4.1 software (Waters) was used to deconvolute the mass spectrum.

Average molecular mass of chitosan oligomers was determined using ESI-MS. Samples were dissolved in 50% acetonitrile containing 0.2% (v/v) formic acid. A 100 μL (0.3 µg/µL) aliquot was centrifuged at 8,000 g for 5 min and loaded directly onto a nanoelectrospray ion source (nanoES) coupled to a Synapt HDMS ESI-Q-ToF mass spectrometer (Waters Corp., Milford, MA, USA). The instrument was calibrated with phosphoric acid clusters. Mass spectra were acquired by scanning at m/z range from 100 to 1,500, at a rate of 1 scan per second. The mass spectrometer was operated in positive mode, using a source temperature of 363 K and capillary voltage at 2.5 kV. Data collection and processing were controlled by Mass Lynx 4.1 software (Waters).