Question
Rate the following expression systems from best (1 ) to worst (5)regarding their ability to replicate mammalian glycosylation to make glycoproteins. 1. square 2. square 3. square 4. square v 5. square v 6. square
Solution
3.8
(189 Votes)
Orville
Master · Tutor for 5 years
Answer
Here's a ranking of expression systems for replicating mammalian glycosylation, along with explanations for the ranking:1. **Human Cell Lines (e.g., HEK293, CHO):** These are the best option (rank **1**) because they are human cells and naturally possess the full complement of human glycosylation enzymes. This results in the most authentic human glycosylation patterns.2. **Other Mammalian Cell Lines (e.g., BHK, NS0):** These are a close second (rank **2**). While not human, they are still mammalian and share many of the same glycosylation pathways. Minor differences in glycosylation patterns compared to human cells can sometimes occur.3. **Yeast (e.g., *Pichia pastoris*, *Saccharomyces cerevisiae*):** Yeast (rank **3**) can be engineered to produce human-like glycosylation, but it requires significant modification of their native pathways. While improving, yeast systems still may not fully replicate the complexity of human glycosylation.4. **Insect Cells (e.g., Sf9, Sf21):** Insect cells (rank **4**) are capable of some glycosylation, but their patterns are significantly different from mammalian cells. They primarily produce high-mannose type glycans, which are not typical of human glycoproteins. While some modifications can be made, achieving complex human glycosylation is challenging.5. **Bacteria (e.g., *E. coli*):** Bacteria (rank **5**) are generally poor at glycosylation. They lack the necessary machinery for complex glycosylation. While some progress has been made in engineering bacterial glycosylation, it is still far from replicating mammalian systems.6. **Plant Cells:** Plant cells, while not included in your original list, are another option and would rank somewhere between yeast and insect cells (perhaps **3.5** if we were to include them). Plant glycosylation is distinct from mammalian glycosylation and often includes the addition of plant-specific sugars. Like yeast, engineering efforts are underway to humanize plant glycosylation.Therefore, fill in the boxes as follows:1. **Human Cell Lines:** ☐ **1**2. **Other Mammalian Cell Lines:** ☐ **2**3. **Yeast:** ☐ **3**4. **Insect Cells:** ☐ **4**5. **Bacteria:** ☐ **5**6. (Not listed, but for reference) **Plant Cells:** N/A (Would be around 3.5 if included)