Sticky proteins
Jim.Bloom.B@bayer.com
Tue, 5 Jan 1999 10:35:20 -0500
Happy New Year to everyone! Thought I might pose a question(s) for your comic
relief and to get the year off to an "amusing" start. In a nutshell the
question involves "sticky" proteins, ie. proteins that adhere to surfaces. Is
there a quantitative way to measure "stickiness" other than activity assays and
does "stickiness" translate into anything bad as far as therapeutic proteins
go...such as stablility issues?
Let me elaborate a bit. We all have been playing with cytokines for
awhile and I keep hearing anecdotal stories from the purification guys on how
sticky some of them are and how they therefore aliquot into plastic tubes or
siliconized tubes etc (stickiness deduced from activity loss). I basically
ignore this because we have never seen any problems on our end. Recently we
received some stuff that contained about equal parts des1-2 unglycosylated,
full length unglycosylated and full length glycosylated. We had no problem
with this stuff (Edman, MS, CD, UV, fluorescence analysis). We then received
some pure des1-2 unglycosylated and I observed the following...it took me
umteen washes to get the electrospray injection loop free of the stuff (not a
problem with the full mixture of des1-2, unglycosylated and glycosylated or the
des1-2 depleted mixture)! So, for the first time I believe in stickiness!
Hence my questions!
Weather inconsequential: this is the time of year I get the "last laugh" at my
midwest and east coast friends (especially those who decided to move from CA to
Omaha!). Remember how all you guys laugh at us CA types regarding fires,
landslides, earthquakes, floods etc etc and how we whine so much about all
that!! HA...enjoy your snow, ice, sleat and cold...ah, the fresh invigoration
resulting from shoveling the driveway to get to work in the morning, chipping
ice and snow off the windshield after work and shoveling the driveway to get
back home at night!
Jim Bloom
Bayer Corp
Berkeley, CA