UPDATE: The three molecules are preproinsulin, proinsulin, and insulin. The pathway depicts the processing of the newly synthesized prepro- form. The first step is removal of the signal sequence in the endoplasmic reticulum. The signal sequence helps target the molecule for secretion. The second step is cleavage of proinsulin to remove an internal segment of the polypeptide chain. The completed molecule has several disulfide bridges. Such bonds are characteristic of secreted proteins. They help maintain the structure in the harsher environments found outside of the cell.
The Nobel Laureates are Frederick Banting and J.R.R. Macleod. Banting, Best, Macleod and Collip, who all ended up with a share of the prize money, worked in a lab that's on the same site as my office, where Sandwalk is mostly produced.
This week's winner is Maria Altshuler of the University of Toronto.
Identify all three molecules shown here. Be as specific as possible.
There's are several possible Noble Laureates associated with these molecules. I'm looking for the one(s) who got the first prize. There's a special connection to Sandwalk, can you guess what it is?
The first person to identify the molecule and the Nobel Laureate wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first won the prize.
There are seven ineligible candidates for this week's reward: David Schuller of Cornell University, Nova Syed of the University of Toronto, Dima Klenchin of the University of Wisconsin and undergraduate Alex Ling of the University of Toronto, and James Fraser of the University of California, Berkeley, Guy Plunket III from the University of Wisconsin, and Deb McKay of Toronto.
David, and Dima have offered to donate their free lunch to a deserving undergraduate so I'm going to continue to award an additional free lunch to the first undergraduate student who can accept a free lunch. Please indicate in your email message whether you are an undergraduate and whether you came make it for your free lunch (with a friend).
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Laureate(s) so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.
Correct responses will be posted tomorrow. I reserve the right to select multiple winners if several people get it right.