Sulaiman N. Depamede
ABSTRAK. A 14.2 kDa protein isolated from Bali cattle (Bos sondaicus/javanicus) saliva has been reported to have a bactericidal activity. The aim of this study was to analyse the nature of a 14.2 kDa protein using single dimension (1-D) sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometer (MALDI TOF/TOF). The protein was isolated by means of polyethylene glycol (PEG)/sodium sulfate aqueous twophase system, and then determined by 12.5% SDS-PAGE. A band of 14.2 kDa was sliced and analysed by MALDI TOF/TOF mass spectrometer using a 5800 proteomics analyzer. Mascot search and National Center for Biotechnology Information (NCBI) Blast search revealed that the spot of 1-D SDS-PAGE consisted of three proteins: zymogen granule protein 16 homologue B, pancreatic adenocarcinoma upregulated factor-like, and prolactin-inducible protein homologue precursor. The three proteins have been observed in Bos taurus and other species such as mouse. The actual nature of the proteins and their function in Bali cattle (Bos sondaicus/javanicus), as well as the connection with the evolution of bovines need further analysis.