Chapter 6 Post

AKP-Vm, a Novel Alkaline Serine Protease


This article from PubMed is about an extracellular alkaline serine protease. It was secreted by Vibrio Metschnikovii (V. metschnikovii) ATCC700040 cells and was refined by 3 chromatographic steps to be characterized in terms of enzymatic kinetics and substrate specificity. 


AKP-Vm, the purified enzyme was comprised of a single polypeptide with a molecular weight of 50 kDa on 12% SDS-polyacrylamide gel in the presence of CuCl2. The optimal temperature for the enzyme was found to be 37 degrees Celsius and the optimal pH was 9.5. But the enzyme activity was inhibited by inhibitors such as aprotinin and PMSF. AKP-Vm was able to hydrolyze a peptide bond at the carboxyl end of the arginine residue, as shown by its amidolytic activity toward a chromogenic substrate, Boc-Val-Pro-Arg-pNa. The kinetic limits of the enzyme were: KM=0.91mM, kcat=0.8 sec-1 and kcat/KM=0.88 mM-1sec-1. 


AKP-Vm protease was able to cleave numerous blood coagulation-association proteins, including fibrinogen, prothrombin and thrombin. Specifically, the enzyme displayed powerful fibrinogenolytic and fibrinolytic activities, as it was able to cleave all major chains of fibrinogen and digest cross-linked fibrin. The results propose that AKP-Vm is a novel alkaline serine protease that can actively cleave fibrinogen and cross-linked fibrin.


Catalysis


I found this useful interactive animation. It shows about how reactions are driven by energy, and how enzymes act as catalysts to increase the rates at which reactions take place. It uses the ball rolling down the hill example in addition to other real-world examples. Also, it lets you add an enzyme and see the effects of it.  The animation even tests you with pop-up questions along the way to see if you're paying attention! But don't worry if you get any wrong; the animation will give you the right answers and explain why they are right.


Entropy and The 2nd Law of Thermodynamics

This video is very interesting, to say the least. It discusses entropy and the second law of thermodynamics. Everything seems to be more interesting as a song, even entropy! The lyrics go really fast, so I would suggest reading them in the info bar of the video. I like how it relates entropy and the second law of thermodynamics to real life examples. And it also does a good job of defining and explaining what entropy really is. In addition, the video mentions the scientists who contributed to our knowledge of this subject. It never hurts to learn some history. Watching this video taught me about entropy and the second law, plus it made me laugh. I think learning is most effective when it's entertaining, so hopefully everyone else can get some enjoyment while learning!