Changye and Yong’s first paper, up as a preprint at PeerJ
in accord with my 2015 and 2014 New Year resolutions describes an accidental discovery. One of their co-authors, Sarah Taylor, was exploring HaloTag as an alternative means of labelling protein to green fluorescent protein, and I thought it would be good to be able to have a pure in vitro system to validate labelling. So Changye and Yong made some recombinant HaloTag fibroblast growth factor-2 (HT-FGF2). When they showed me the gel, they noted that HT-FGF2 did not seem terribly promising, because there was quite a lot of protein in the bacterial pellet.
It is at this point that the professor earns his keep,
because in years of expressing FGF2, we have never managed to jack expression levels up to the point where we get insoluble protein. The problem is that with full-length FGF2, the 5’ mRNA sequence that encodes the protein’s N-terminus is highly structured and this inhibits translation (N-terminally truncated FGF2 expresses at crazy levels, but we like punishment and make the full-length protein). My reaction to the gel was, “Wow, this is cool, we have made more protein than ever before, maybe HaloTag is a good solublisation tag?”
So I convinced Changye and Yong to test out HaloTag fusions of some of the FGFs that we could not express as soluble proteins. The rest, as they say, is history, and we have a preprint and a paper submitted out of the blue.
Chance favours the prepared mind. I guess this shows that one aspect of the prepared mind is experience in the form of attention to the detail of experiments and of data and one of many good reasons to favour not just open access publishing, but also open data. Meanwhile a couple of collaborators overseas have taken this on board in the last month to try to solve their expression problems. Hopefully HaloTag will work for them too, so I can claim the usual intellectual property tax – one beer – though if this spreads too far I will forgo some of my earnings on the grounds of health…