The important role of chromatography in the lab

Chromatography has taken a prominent place in the characterization and analysis of protein therapeutic drugs and today it plays a critical role in the biotechnology laboratory. Although reversed-phase chromatography is the foremost chromatography technique used for this purpose, other techniques such as ion-exchange, size-exclusion, normal-phase, hydrophilic-interaction, and hydrophobic-interaction chromatography play very specific roles in characterizing and analyzing protein drugs.

Chromatography has long been an essential tool for protein purification. Dextran-based ion-exchange and size-exclusion columns have been instrumental in protein purification and characterization for decades. With the development of recombinant DNA proteins for therapeutic purposes there has been a need for careful, detailed characterization of these proteins, the changes and modifications that might occur, as well as sensitive determination of changes that actually occur. Chromatography has taken its place as a premier technology in both the characterization and the analysis of recombinant protein therapeutic drugs (1).

Protein Modifications and Their Effect on Protein Therapeutic Drugs

The biological activity and, therefore, the therapeutic efficacy of protein drugs depend on the exact composition and three-dimensional structure of the protein. Any change to a protein (modification) may affect its efficacy as a therapeutic agent, although efficacy may not be affected by some protein modifications. The effect of a given modification depends on the protein and the nature and location of the modification. During development of a protein therapeutic drug it is necessary to fully characterize the protein, define what possible modifications may occur, define those modifications that do affect efficacy (critical quality attributes), and develop methods to analyze such modifications. Changes occur to proteins from the beginning of their assembly. Some changes may be needed for the protein to be properly formed into an active tertiary structure such as glycosylation and disulfide bonds, which are critical in maintaining the proper structure. Glycosylation attaches sugar chains to either asparagine or serine residues. These sugar chains affect protein folding and assist in maintaining correct tertiary protein structure. Glycosylation structure is complicated and is affected by the cell lines used for protein expression as well as other aspects of the expression system. It is vital to characterize and monitor glycosylation patterns. Disulfide bonds formed between cysteine residues are essential for formation and maintenance of proper tertiary structure. These must be characterized as to their locations in the primary structure of a protein and also must be monitored to ensure that a protein remains active.

Other modifications may affect protein binding and reduce activity such as chemical deamidation — the conversion of an asparagine residue into an aspartic or isoaspartic acid residue under conditions of high temperature or high pH — and oxidation of methionine residues under chemical oxidative conditions to methione sulfoxide. These two modifications may affect activity if found near catalytic or binding sites, but may have no effect if found distant from sites of activity.

Some modifications are engineered into proteins to form more effective drugs. The addition of polyethylene glycol to proteins — pegylation — usually extends the duration of protein activity in the blood stream several times by reducing the rate at which the protein is removed from the blood stream. Monoclonal antibodies (mAbs) that bind to specific receptors on the surface of tumor cells can be modified by the addition of highly toxic drugs to the monoclonal antibody, creating a highly specific, effective reagent that targets and kills specific tumor cells. Engineered modifications must be analyzed and monitored.

Proteins may lose tertiary structure by variations in pH, temperature, or the presence of certain reagents. Such “denatured” proteins lose biological activity and pharmacological potency. Proteins may also form “aggregates,” where multiple proteins self-associate into larger complexes that usually reduce activity and may engender immune responses in patients.

Importance of studying Technological Sciences in the 21st century

Quest for a school

A week ago, I began my classes at a university in Yemen. Having been born and raised in Sana’a, I had a variety of universities and colleges to choose from that were in the vicinity of my home. That meant my campus education was not going to be far from my family. This was my plus as I did not have the task of finding accommodation in or around the school I picked.

My choice of school was simple. I wanted to be involved in the health development of our nation, and after doing my research online for the most suitable school. I found a school, located in Sana’a and which was also international accredited. A bachelor’s degree in Health and Society was exactly what I was looking for to achieve the life goals of being a health policy maker in Yemen.

School commences

Sitting in the classroom hall waiting for the lecturer to arrive, I decided to check some important emails that pertained to my class schedule. Up until that point I had never brought my laptop along with me to any of my classes. However, on this particular day, I decided to carry it as there were assignments I needed to submit and articles I was expected to complete. Thus since I usually arrived earlier than everyone else in my class, it made sense to have my laptop and use that time completing the assignments than day-dreaming or playing games on my phone (I am somewhat of a fanatic).

With my laptop, ready I went on to check my emails first. However, I had not carried my modem thus opted to use the school’s network. Furthermore, I had paid for the same. Clicking on the network icon, a series of networks available were listed. I found the school network and clicked on it to connect. As usual, a password was required. My next option was to head to the ICT department to acquire the password so that I could proceed with my work. Let me just first say that I had been using the internet for a very long time. Whether it was for leisure or for the part time writing job I did that required research on the internet.

That said, I cordially asked for the password only to be told that they needed my laptop so that they could configure it, to be able to access the school’s internet.

This, my friends, was what led me to write this piece. I have always understood the need for IT specialists in the world of technology, but I never thought that I would personally ever need their assistance. The truth was that I had taken my ability to access for granted. I figured that the computer would do everything if I clicked the right icon, as simple as that. Like many people, such as I, who take access to the internet for granted, I realized that this access had be:

set up
fixed by IT specialists

Technology and the 21st century

This got me thinking of the major role that information technology (IT) plays in the 21st century. A few years ago, having a computer was more or less a luxury. However, in this day and age, it is practically impossible to do most things without it. The mobile phones we use are basically modified computers; the new models are seemingly a replacement of desktop computers as well as laptops.

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