Pharyngula

This last week in Biochemistry

It’s been quite busy last week. Despite the Neurobiology class didn’t meet that week, my other classes kept my hands full. I blame it on two exams and a paper due during the week of Homecoming.

Since I don’t have any new thoughts on Neurobiology, let’s see what can be dug up from my Biochemistry class. For the lab, I wrote my paper of Desulforedoxen. Its job is reducing sulfates. You can look it up at JMol using “1DHG” as the code.

I found this protein very interesting. In class, we had learned about the driving forces for tertiary structure in proteins: H-bonding, hydrophobic/Vanderwal’s, salt bridges, and disulfide bonds between Cystine residues. Upon examining Desulforedoxen, I learned that Cystines were capable of more than just S-S bonding. With four Cystines clustered nearby each other in the tertiary structure, an iron atom sits tetrahedrally bonded to the four sulfurs. While I bet it is a major player in tertiary structure, it just reeks of active site. Since the transition metal, and its neighboring sulfurs, have ‘D’ orbitals, this looks like it’s capable of something that can’t easily be performed in a test tube.

I’ll be a lot of you already know that this can happen in proteins. For me, it was learning it by observation instead of in lecture, that was fun. Moments like that have made it well worth it to go into biology. It’s also cool how such lesser-used amino acids have more than one purpose that they can serve in cells.

Note: the article I read about this protein said that it had iron bonded to the sulfur. When I looked it up in JMol, it was instead bonded to mercury. Weird. An abstract of the article I used can be found here. Anyways, just washing my hands so I don’t fall victim to the inconsistencies-lynch-mob. Have a nice day.