•March 17, 2008 •
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Hey everybody, sorry about my tardiness with this post. The week has been very hectic with many exams and I found it difficult to sit down and collect my thoughts in order to make a coherent and efficient blog post.
Up to now the month has been very productive. The lab team has been helping me familiarize myself with the many techniques that are used in this investigation. (For a guy who is currently majoring in Biology; a research opportunity in an Inorganic Biochemistry lab is quite a challenge!). Nonetheless they have been very helpful in “bringing me up to speed” with the lab’s recent accomplishments. I have also been taught the many mathematical calculations that are needed before an experiment commences.
Currently we are preparing to begin a protein crystallization experiment that will help us determine the adequate sulf-hemoglobin crystallization concentration. Crystallizing a protein is one of the most difficult tasks and it must be executed with total control of all chemical parameters. There cannot be any discrepancies in regard to ambient temperature, protein concentration, pH and pI. This is because once we have crystallized the altered protein it will take one year to receive the X-Ray irradiation results. So if the protein was not crystallized perfectly then we will never know what is it’s third dimensional structure.
Up to now working in a laboratory team, has been a unique experience. Although at times I want to jump at the opportunity to have responsibility and independence in the lab I must also take into account that what I do in the lab affects the other members of the team. Up to now; we are getting along perfectly but it requires a lot of coordination of schedules so that we all are present in the lab when the experiments are underway.
The lab experience has been a fascinating adventure and I am overjoyed to learn new and exciting things. The most important factor that will determine the success in BioMinds will nonetheless be the teamwork that has been put into the project.
Well thanks for reading… Hope to hear from you soon!
I hadnt published this!!! Sorry!!! I just noticed it now!
Posted in BioMinds (general), Something New
•February 10, 2008 •
7 Comments
The research mentor that I chose and was accepted by for the Biominds experience is Dr. Juan López-Garriga of the Chemistry Department. The scientific research that is currently conducted by him entails the study of hemeproteins, such as Hemoglobin I from the clam Lucina pectinata.
I was highly interested in this topic due to a Biochemistry class I had taken last semester. The inner workings of Hemoglobin and Myoglobin are incredibly fascinating to me. I wanted to explore this topic in a laboratory setting, to its fullest extent, and gain as much knowledge as I possibly could in the relatively short period of three semesters.
After consulting with Dr. López-Garriga, I was appointed to work with a graduate student that specializes in the study of sulf-hemoglobin. Sulf-hemoglobin is the result of a physiological intoxication with H2S.
The active site of Hemoglobin is formally known as the Protoporphyrin IX (shown above). In this area the FeIII atom is located, along with 4, five-membered pyrrole rings. When intoxication with H2S occurs, the sulfur atom binds irreversibly to the B pyrrole (illustrated above). This non-reversible reaction completely disables the normal hemoglobin. The active site is now obstructed and the iron atom cannot exert its physiological task (EVER AGAIN!). This catastrophic reaction can occur due to an overdose of certain pharmaceutical agents that may stimulate the physiological production of H2S in the human body.
Curiously there exists a clam known as Lucina pectinata (Invertebrata; Mollusca; Bivalvia) that is involved in a very special symbiotic relationship with intracellular chemoautotrophic bacteria. The clam, Lucina pectinata, possesses 3 different forms of hemoglobin known as HbI, HbII, and HbIII. As a result of the symbiosis, the clam is subjected to varying concentrations of H2S in its natural environment. The HbI has the ability for binding to sulfur at the FeIII atom and not the B pyrrole. This advantage allows for the effective transport of sulfur (for the hungry bacteria) throughout the clam. The clam’s hemoglobin does not lose its chemical activity as what occurs to human Hemoglobin.
In order to understand which intermidiaries are present in the reactions of sulf-hemoglobin formation, we must fully comprehend the 3-D structure of the product (sulf-hb). The method of producing this is by means of X-RAY crystallography. The objective for this semester (mine and my lab group’s) is to succesfully cristallize sulf-hemoglobin. By crystallizing this catastrophic form of Hemoglobin we can then identify the amino acids and chemical intermidiaries and then compare them to Lucina pectinata’s HbI. Such study of hemoglobin can lay down an infinite ammount of possibilities regarding the study and alteration of Hemoglobin. By doing this we could help and possibly find a alternate remedy for patients who suffer from poisinous gas intoxication.
Up to the moment my mentor has brought me up to speed on the lab’s recent achievements and has also provided me with scientific journals related to the topic of hemeprotein study. At the moment we are now preparing sulf-hemoglobin (under the proper laboratory conditions) to then effectuate the crystallization.
Sulf-hemoglobin formation results from the following reaction:
Hb + H2O2 + H2S = sulf – Hb
More to come soon… crystallization is near!
Posted in BioMinds (general)
