Ask A Scientist: Proteoglycans vs. Glycoproteins

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The extracellular matrix is a complex combination of non-cellular materials that support biochemical and biomechanical processes in the tissues and organs. Among the components of the extracellular mix are two distinct types of biomolecules: proteoglycans and glycoproteins.

Immunology researchers are primarily interested in these biomolecules due to their role in the human tissue processes and immune system function. For example, scientists have researched the effects of proteoglycans and glycoproteins on wound healing, liver cancer, viral pathogens, and many other areas.

Measuring Proteoglycans

Detecting proteoglycan in your tissue samples is a two-part process. First, properly prepare your tissue samples using the optimized assay buffer and detailed instructions in the Tissue Digestion Kit. Next, measure sulfated glycosaminoglycans with a simple colorimetric readout in the Proteoglycan Detection Kit.

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The Differences Between Proteoglycans & Glycoproteins

Learn more about the differences between proteoglycans and glycoproteins in the table below.

comparing proteoglycans and glycoproteins

6 thoughts on “Ask A Scientist: Proteoglycans vs. Glycoproteins

  1. Jared Gerlach says:

    Hi Anne,

    This is a great post, but the numbers for the carbohydrate content are reversed. It’s 50-60% for the proteoglycans and 10-15% for most common glycoproteins (and things like uromodulin and most mucins would be 30+% sugars).

    Best,

    Jared Gerlach

    • Anne Lodge says:

      Well I stand corrected. I don’t know where I found the higher percentage for glycoproteins but your figures make more sense to me, especially given the function of proteoglycans.

    • Anne Lodge says:

      That’s a good question Lance. I was referring to articular cartilage when I wrote that, not thinking about other forms of cartilage. It could be that in a shark fin or external ear of a mammal there would be less glycosaminoglycan because those tissues are stiffened by the proteoglycans but not bearing weight as in articular cartilage. You could certainly check with a longer hydrolysis of the sample to be sure you have freed up all the GAG. With our tissue digestion kit we could clearly see an increase in glycosaminoglycan with increasing digestion time.

  2. Charan Amogh Raj says:

    I am a student and i have a doubt. If carbohydrates are core to glycoproteins then why is the amount of carbohydrates less in glycoproteins than proteoglycans?

    • Anne Lodge says:

      I understand your doubt. I think of both glycoproteins and proteoglycans as having a protein core. One description of proteoglycans is to think of them like a test tube brush. The protein in the middle with the bristles being carbohydrate chains. With proteoglycans the proteins are usually longer and carbohydrates are placed at points along the protein sequence. In both cases the beginning is a protein but in the case of proteoglycans it is totally surrounded by carbohydrate.

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