Date: Thu, 23 Jan 1997 13:37:00 -0500 (est)
From: "Williams, Ken" <WilliamsKR@MASPO1.MAS.YALE.EDU>
Subject: FW: C-terminal blocking
To: Recipients of ABRF List <abrf@aecom.yu.edu>
Copy of a response to my question regarding extent of C-terminal blocking of
proteins that I received from Finn Wold and that he agreed to post.
Ken Williams
_______________
From: fwold
To: Williams, Ken
Subject: Re: C-terminal blocking
Date: Wednesday, January 22, 1997 11:59AM
Ken:
I am not sure that I have an answer for you. According to my
records, the only C-terminal blocking reactions are the following:
1. -Amide (Kreil, 1984; Bradbury and Smyth, 1991).
2. O-(ADP-ribosyl)- (Hayaishi and Ueda, 1984; Adamietz and Hilz, 1984).
3. O-Methyl- (Inglese et al., 1992; Clarke, 1992).
4. -(N-Ethanolamine-glycan-phosphoinositides) (Englund, 1993; Udenfriend
and Kodukula, 1995).
5. -(Na-Tyr) (Flavin and Murofushi, 1984; Webster et al., 1987).
Of these, 5 is not really blocked, since it simply represents the addition
of Tyr to the C-terminus. (C-terminal sequencing would not be affected).
1, 2, 3 and 4 are probably true blocking groups, but the methods used for
the sequencing would undoubtedly affect the relative accessibility of the
C-terminals for sequencing, especially in the case of 1 and 3. 2 and 4 are
not very common, so they should not represent major hurdles to C-terminal
sequencing.
Best regards, Finn