Take the 2-minute tour ×
Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It's 100% free, no registration required.

I have just an intuition that the carbohydrate part of glycoproteins help them to fulfil those tasks like in plasma membranes. You can also get many more receptors if you can use carbohydrates too.

For instance, glycoproteins are necessary in recognising white blood cells. Antibodies are examples of glycoproteins. So they play a crucial role in our innate and adaptive immunity: MHC interaction with T cells in adaptive immunity. Other examples: necessary in platelet aggregation and adherence, components of zona pellucida and connective tissue. Some hormones are also glycoproteins so necessary in humoral adaptive immunity: FSH, LH, TSH and EPO.

But why glycoproteins are "better" than proteins without carbohydrates moiety in fulfilling biological tasks?

I still see that both are important, but why the one is better than the other one.

In other words: Are there any biological tasks that only non-glycoproteins can fulfil, not glycoproteins? Are non-glycoproteins necessary in some essential biological tasks?

I think the answer to the last two questions is "yes", so why would one say that glycoproteins are better in fulfilling biological tasks than non-glycoproteins.

share|improve this question
4  
Essentially all cytosolic, nuclear and mitochondrial proteins are non-glycoproteins, so I think that the premise of the question is flawed. In fact, it isn't really clear what you mean by "better". –  Alan Boyd Oct 27 '12 at 16:26
    
@AlanBoyd I completely agree with you. The thing is that the teacher wants explanations why some thing is better than other. I however do not see any sense in it. It is like comparing bananas with apples. –  Masi Oct 27 '12 at 17:33
1  
@masi, there are good reasons why membrane bound glycoproteins are suited for certain tasks. You cannot generalise though, it depends on the task in question. –  terdon Oct 27 '12 at 17:59

1 Answer 1

up vote 2 down vote accepted

The central reasoning is flawed because it places some intrinsic value on glycoprotein modification. The general intuition is that, if the protein is glycosylated, then it's likely for a reason, whether it be to help fulfil antigen recognition, adopt a correct conformation, or help in molecular tethering. Beyond, that, many (perhaps a majority) of cellular proteins are not glycosylated. Two important examples of cell membrane proteins that are not glycosylated would be endoproteases (eg, furin) and chemical transporters.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.