Fig. 2

Molecular weight analysis using mass spectrometry. His₆-PrS₂-Bac7 (1–35) was cleaved by factor Xa protease and the reaction mixture was diluted 25 times by the matrix solution containing sinapinic acid (10 mg/ml) in 0.1 % trifloroacetic acid and 50 % acetonitrile) and spotted on to a target plate (Opti-TOF 384 well insert, ABSciex) and air dried, followed by mass spectroscopic analysis by a MALDI-TOF using the positive mid-mass linear mode from 2 to 30 kDa. Peak A (4.21 kDa) represents Bac7 (1–35) fragment, peak B (10.85 kDa) represents the PrS fragment, and peak C (21.68 kDa) represents the PrS₂ fragment