Analysis of neutrophil proteins of patients with Behcet's disease by two-dimensional gel electrophoresis

Protein changes in the neutrophils of patients with Behcet's disease were a nalyzed by high resolution two-dimensional gel electrophoresis to investiga te the pathological features of Behcet's disease. Two clear protein spots w ere found to be differently expressed between healthy volunteers and patien ts with Behcet's disease. One was a 53 kDa protein with pI 5.2 that was det ected in healthy volunteers but was nearly absent in the patients. The othe r was a 40 kDa protein with pi 5.2 that was detected in the patients but ne arly absent in the healthy volunteers. Analysis of the N-terminal amino aci d sequence of the 40 kDa protein revealed that it was a truncated actin wit h an N-terminus of Met-44. The presence of the truncated actin in the neutr ophils of patients was confirmed by Western blot analysis using an antibody to the C-terminus of actin. The 53 kDa protein could not be identified bec ause its N-terminus was blocked. The presence of the truncated actin in the neutrophils of the patients may be important in understanding the patholog y of Behcet's disease.