Oral Insulin Delivery Cover Image (And Associated Syracuse Research Article) in ChemMedChem

You've heard about it, you've read about it, you've seen it on color TV, you've even seen it streamed. The cover story in this month's issue of ChemMedChem is a communication by members and collaborators of the Robert Doyle Group here at Syracuse University. The report describes the B12/TCII-based uptake of insulin, a process that occurs via the ingestion of a B12-insulin conjugate. In case you missed that, the delivery is oral, not by needle. For those of us that pass out at anything needle-related at about the time that the alcohol wipe is opened, that's a positive step forward for getting rid of any syringe-related medicine altogether.

full image

With the cover story comes the cover image shown above, a structure calculation on the insulin-B12/TCII complex. The bases for this structure can be found in the Protein Data Bank, including the TCII-B12 complex reported in PDB entry 2BB5 (the only hack in the structure calculation involved the replacement of the cobalt for iron to use already available bond parameters) and the insulin structure reported in PDB entry 1ZNI. The covalent attachment of the insulin to B12 can be found in the article. Structure manipulation was performed with a combination of NanoEngineer-1 and VMD, VMD being included in the mix in order to generate the ribbon renderings of the insulin and TCII protein backbones. As for the accuracy of the calculation, time and a synchrotron X-ray source will tell.

For much more information and numerous links to new stories related to the research in the article, I direct you to the group website of Robert Doyle and the various links to news stories available in his departmental publication list.

chemmedchem cover
From ChemMedChem. Click HERE to go to the article.

From the website:

Cover Picture: Vitamin B12 as a Carrier for the Oral Delivery of Insulin (ChemMedChem 12/2007). The cover picture shows an orally active, glucose-lowering vitamin B12-insulin conjugate bound to the B12 uptake protein transcobalamin II (TCII). The inset shows a close-up view of the TCII binding pocket. (Insulin is in red; vitamin B12 is in bright yellow.) For details, see the Communication by T. J. Fairchild, R. P. Doyle, et al. on p. 1717 ff.


POV-Ray The Error Number Is -199 Potential Remedy For OSX

This post provides a possible fix for an OSX POV-Ray error with precious little information available about it anywhere online. The error,

The Error number is -199. (For internal reference only!)

appears upon startup and exits from the program proper, such that POV-Ray becomes useless (not pleasant when you need that last minute image 30 seconds before lecturing).


The only mention online (if you search by the message text) can be found at


The error itself is not diagnosed, only noting that a corrupted file is not being accessed upon startup and that running a Disk Utility verification/fixing and reinstalling POV-Ray solves the problem. If this has happened to you, you may have noted that verification/fixing and re-installation does not do the trick.

The origin of the problem on my machine could be traced to a crashed POV-Ray rendering run of a number of images and the retention of the file POV-Ray Mac 3.6.plist in my /[USER]/Library/Preferences/ directory, which typically only contains the file POV-Ray Preferences 3.5 (why an installation of POV-Ray 3.6 would still leave a 3.5 Preference file is beyond the scope of this post).

Deleting the POV-Ray Mac 3.6.plist file fixes the problem.