Thiohydantoin formation and selective modification of the carboxy terminus of an aspartic acid- and/or glutamic acid-containing protein
US5665603A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 1994 |
| Grant date | Sep 9, 1997 |
| Priority date | — |
| Expiry date | Jul 8, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/6821
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of forming a thiohydantoin from an N-protected amino acid is described. The method employs a phosphate compound selected from the group consisting of EQU (R.sub.1 O)(R.sub.2 O)P(.dbd.O)X and EQU (R.sub.1 O)(R.sub.2 O)P(.dbd.O)--O--P(.dbd.O)(OR.sub.3)(OR.sub.4) to form acylphosphate moieties from the carboxyl groups of internal aspartic acid and glutamic acid residues and an acylphosphate moiety at a C-terminal carboxyl. The later acylphosphate, unlike the internal acylphosphates, spontaneously cyclizes to an oxazolone, which is less reactive with nucleophilic reagents. R.sub.1 and R.sub.2 are each alkyl, aryl, or alkaryl groups which are the same or different and which may be covalently linked to each other; R.sub.3 and R.sub.4 are each alkyl, aryl, or alkaryl groups which are the same or different and which may be covalently linked to each other; and X is a leaving group, such as chlorine or bromine, which is substantially unreactive towards thiohydantoins. The acylphosphate and oxazolone moieties are then reacted with a thiocyanate reagent under conditions effective to convert the internal acylphosphates to amides and the terminal oxazolone to thiohydantoin, thereby perm…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.