More About Laminin

Previously, I had blogged my opinion on the protein Laminin and its supposedly “cross” shape. The shape of this protein was seized upon by one evangelist, Louie Giglio to support a proposition in his sermon. I did not know much about the protein at that time (except what I wrote in that blog) and I was reluctant to believe that a scientist would say that the protein was “cross” shaped partly due to the sensationalism of Louie, I must admit. However, I now have found some interesting information regarding this protein’s role in cancer research.

Recently, whilst I was reading the [excellent introductory pathology and core text in my course] book, Cell, Tissue and Disease by Prof. Neville Woolf (2000), I came across this little paragraph about laminin:

“Laminin is a cross-shaped glycoprotein present in both the basement membrane and the interstitial stroma. In normal cells laminin receptors occur on the aspect of the cell apposed to the basement membrane and are occupied by basement membrane laminin. Invasive cells, however, have laminin receptors diffusely distributed over the entire cell surface and these are often unoccupied. If such tumour cells are treated with the receptor binding fragment of laminin, their invasiveness is greately reduced” [my emphases]

Firstly, the author refers to this protein explicitly as “cross-shaped”, so Louie’s description was accurate. Secondly, it appears Laminin fragments reduce the metastatic potential of a neoplastic (tumorous) growth and hence, rids the neoplasm of its dangerous property. This potential therapy can be used if the cancerous growth had not metastasized already. Even if the cancer has spread, it could (in theory) arrest further spreading. It should be noted that this is less likely to happen naturally even when there is enough laminin in the body [to arrest the spreading of a cancer] because there is little laminin fragments freely floating around in the body. I suspect that the laminin fragments have therapeutic potential because they don’t have the binding domain for the basement membrane, otherwise (I think) they might actually help the invasive cell to adhere to the basement membrane and achieve malignancy easily!

So, the cross shaped Laminin not only proves God’s promises to be true, it helps scientists to cure cancer! 

The Tetrahymena Puzzle and the Origin of Life

Over at Telic Thoughts, Bilbo had a repost of Mike Gene’s Tetrahymena Puzzle. Tetrahymena I should know is one of the model organisms in Genetics just like the Drosophila fly. After racking my sophomoric brain for two days trying to come up with an answer, I failed. Now Mike has revealed the answer over at his blog.

The Puzzle:

Lets begin by making a media with the following ingredients: amino acids, glucose, vitamins, nucleosides, salts and citrate. Next, let’s transfer a single Tetrahymena cell to 1 microliter of the media. That corresponds to a density of 1000 cells per ml. What happens? The cell does what cells do – it divides and forms a population of cells.

But what happens if you transfer a single Tetrahymena cell to 10 microliters of media (which corresponds of 100 cells per mi.)? Answer – it dies.

So why does this single-celled organism die when it is surrounded by an abundance of food and there are no predators or toxins around?

For the answer, go here.

Mnemonics for Amino Acids

I was searching around for some good Mnemonics or acronyms or anything I could find to remember the 20 essential amino acids names and structures. I found an excellent article here relating the structures of all the amino acids with easy ways to remember them. I’m going to mention things I found helpful for me here.

For those amino acids having non-polar aliphatic side chains, it was suggested that GAVLIMP as a good acronymn. For pronounciations sake it could be like:

G= Glycine

A= Alanine

Va= Valine

L= Leucine

I= Isoleucine

M= Methionine

P= Proline

Put it together, it comes to GAVa-LIMP. Thing is, the structures of the amino acids increase in complexity as you go from Glycine to Proline with Glycine having a hydrogen atom for the “R”- group while Proline has a sort of “penta-cyclic” side chain. Another way I remember this is swapping the first letters of the GAVa and LIMP to give LAVa-GIMP. Those of you that use Linux, will know that GIMP is a famous photo editing cum drawing program. So I picture the programs mascot, Wilber glowing with lava/fire!