Figure 5. SDS-PAGE Analysis of PST Reactions on diSA-fetuin.

A.The three PSTs were incubated with the acceptor molecule disialyl-fetuin using standard reaction conditions (lanes denoted “A”) as well as a reaction condition to improve the formation of the product (13 µg enzyme, lanes denoted “B”) for 1 or 2 h. A negative control reaction (containing no enzyme) was included (“-C”). The small band at ∼75 kDa indicates the PST added to the reaction. B. Following SDS-PAGE analysis, the proteins were transferred to a membrane and probed with α-PSA antibodies. All reactions were positive for PSA except the negative control lane containing unmodified disialyl-fetuin.