I have a essey on "Different Types of HCG hormone" for tomorrow. Could u help me PLZ?
we've been told to find what types does HCG have.
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- " It[HCG hormone] is heterodimeric, with an α (alpha) subunit identical to that of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH) and β (beta) subunit that is unique to hCG. βhCG is encoded by six highly homologous genes which are arranged in tandem and inverted pairs on chromosome 19q13.3 - CGB(1,2,3,5,7,8). "
- I found this on Wikipedia. can you Explain it to me?
- A dimer protein is made up of two subunits (small chunks of protein) stuck together. Heterodimeric means that the two subunits are different; they are usually called alpha and beta, as you point out is true for HCG.
The alpha subunit (as you know from Wiki) is the same one used by other sex/pituitary hormones: FSH, LH, and TSH. The beta subunit, though, is unique to HCG and that's why pregnancy tests look for the presence of beta-HCG.
Encoded by six highly homologous genes - means that the DNA that codes how to make the beta subunit protein is contained in six genes that are very similar (homologous) in their base sequence (CATG etc.) The "tandem and inverted pairs" bit just refers to the order in which the genes are found and read, not particularly important to your question. 19q13.3 refers to their location: on the 19th chromosome (we have 23 pairs plus the pair of sex chromosomes), on the "long arm" of the chromosome (think of it as an X with unequal length arms - p is the short arm, q the long one).
There are a number of forms of HCG around. The link below describes an assay (test to detect presence of molecule) that can detect "all known forms of hCG and its break down products present in serum and urine samples in pregnancy, cancer and trophoblastic disease: regular hCG, nicked hCG, hyperglycosylated hCG, hCG missing the ß-subunit C-terminal peptide, free ß-subunit, nicked free ß-subunit, free ß-subunit missing the CTP, and urine ß-core fragment." All of these are variations/mutations in HCG.
Hope this helps.
- http://www.hcglab.com/assays.htm...