Glossary of Scientific Terms

This is a work in progress. Use ‘reply’ to let me know what terms you would like to see here. Thanks.

Alpha secretase cuts right in the middle of the Aβ part of APP. Any APP molecule that is cut by alpha secretase has had its Aβ portion cut in two, so if half of the APP molecules in a brain are cut by alpha secretase, the potential for Aβ production has been cut in half.

Amyloid is a generic term referring to clumps of insoluble protein. You can have amyloid deposition in many disorders, and as a result of repeated medical procedures like kidney dialysis. The specific protein clumping up and getting deposited varies from disorder to disorder. All amyloids share certain traits. Most important is insolubility. They are tremendously hard to dissolve, which is the reason deposits build up.

APP stands for amyloid precursor protein (or amyloid protein precursor—depending on whose paper you are reading). This is a big protein (in the neighborhood of 700 amino acid subunits long). The much smaller (40-42 amino acid subunits) beta-amyloid protein (aka Aβ) is a small piece snipped out of APP by the secretases discussed last time.

Beta-amyloid The name of the specific protein in the amyloid deposits of Alzheimer’s disease is beta-amyloid protein (a.k.a. beta amyloid, nicknamed Aβ for short). There is a long story about how that name came to be, but suffice it so say that after much initial disagreement, beta-amyloid is the name that was finally generally agreed upon.

Beta-pleated-sheet conformation To a chemist, these words carry meaning and significance. To you and me, all they need to say is insoluble protein. This is the abnormal 3-D shape that proteins take on which make them highly insoluble.

Beta secretase Works with gamma secretase  to free the Aβ section from the big old APP molecule. Beta secretase cuts one end free, and gamma secretase cuts at the other end, releasing Aβ. You only need to stop one of this pair from working to decrease Aβ production. Beta secretes cuts first, then gamma.

Drug names See end of list.

Gamma secretase Works with beta secretase  to free the Aβ section from the big old APP molecule. Beta secretase cuts one end free, and gamma secretase cuts at the other end, releasing Aβ. You only need to stop one of this pair from working to decrease Aβ production. Gamma secretes cuts second, after beta.

 Secretase  An enzyme that act like scissors to cut APP. These scissors enzymes are called secretases because the protein pieces they cut free are released outside the cell (that is, they are secreted— 😉 .   We scientists usually go for the obvious when naming things.)

DRUG NAMES:

I’m afraid I can’t be much help with these…

When drug names look like catalog numbers, that is pretty much what they are—someone is testing a bunch of similar compounds and has numbered them. There is no good way to recall these except to have a good memory. Personally, I don’t try to keep them straight in my brain; I just look them up when I need them.

Chemical names of drugs are sometimes used. These carry useful information only if you are chemist enough to understand them… usually I am not that much of a chemist. I treat these the same as the catalog-type names.

Brand names of drugs are assigned by the companies selling them. While these do sometimes carry meaning, more often they are just made up by some marketing guru employed by the pharmaceutical company.  If you are an Alzheimer’s caregiver, you probably recognize these more readily than I do. Some of the more common I carry in my brain. But even with those, I look them up to be sure I have it straight when writing about them.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s