원문정보
초록
영어
Colostrum differs considerably in the concentration of milk protein that may be more than double compared to later in lactation. Bovine milk contains low concentrations of serum proteins, including albumin, immunoglobulins, complement proteins, members of the IGF family and lactoferrin, compared with human colostrum. This study was performed to identify proteins differentially expressed between bovine and human colostrum. Also, we tried to look for differential proteins between bovine colostrum and mature milk proteins. Whey milk proteins in 3 sets of bovine and human colostrum, which were collected 12h after parturition, were analyzed separately using 2-dimensional electrophoresis (2-DE) within the isoelectric point ranges of 3.0 to 10.0, and then differential proteins were identified using MALDI-TOF analysis. Firstly, in comparison of bovine colostrum with mature milk, a total of 29 protein spots on 2-DE gels were distinctly detected, and protein search analysis revealed that they were identified as polymeric immunoglobulin receptor, zinc-α-2-glycoprotein, vitamin D-binding protein, IGHM protein in bovine milk, etc. Majority of bovine colostrum specific proteins were related with immunity functions. Secondly, we identified 33 differential proteins in comparison of human colostrum with bovine colostrum among which 8 spots were up-regulated proteins in human colostrum samples, 6 spots were up-regulated proteins in bovine samples, 12 spots were human colostrum-specific proteins and 7 spots were bovine colostrum-specific proteins. The identified proteins turned out to be classified in various functional categories. Of these, two human colostrum proteins, IP6K2 and ATP6V1C1 identified in specific human colostrum, were verified with Western blot. IP6K2 protein full name is known to be inositol hexakisphosphate kinase 2 and belongs to the inositol phosphokinase (IPK) family.