CONVERSION OF AN APPARENT 100 KDA FOLATE BINDING-PROTEIN FROM HUMAN-MILK TO A 25 KDA MOLECULAR-SPECIES BY PHOSPHOLIPASE-D

Gel filtration studies in the presence of Triton X-100 showed that treatment with phospholipase D reduced the apparent molecular size of the 100 kDa folate binding protein from human milk to 25 kDa, which is the molecular size of the low molecular weight folate binding protein. A phospholipase D induced cleavage of a hydrophobic phospholipid domain inserting the protein into Triton X-100 micelles could account for this phenomenon.