Abstract: Authentication method and systems using RFID-enabled payment cards are disclosed herein where a server receives a request corresponding to authorization of a payment associated with a payment card from an electronic terminal. The server identifies an electronic device of a user associated with the payment card. The server then transmits an instruction to the electronic device to cause an RFID reader of the electronic device to determine whether an RFID tag corresponding to the payment card is located within a predetermined proximity to the electronic device. When the payment card is located within the predetermined proximity, the server executes a first authentication protocol. Moreover, when the payment card is not located within the predetermined proximity, the server executes a second authentication protocol, wherein the second authentication protocol is more restrictive than the first authentication protocol.

Abstract: The present invention relates to a chemically modified mutant protein including a cysteine residue substituted for a residue other than cysteine in a precursor protein, the substituted cysteine residue being subsequently modified by reacting the cysteine residue with a glycosylated thiosulfonate. Also, a method of producing the chemically modified mutant protein is provided. The present invention also relates to a glycosylated methanethiosulfonate. Another aspect of the present invention is a method of modifying the functional characteristics of a protein including providing a protein and reacting the protein with a glycosylated methanethiosulfonate reagent under conditions effective to produce a glycoprotein with altered functional characteristics as compared to the protein. In addition, the present invention relates to methods of determining the structure-function relationships of chemically modified mutant proteins.