chemical/biochemical severity: what does it mean??

[DaRuSsIaMaN]

Hello everyone. I'm reading a published scientific paper (trying to start interning at the biodesign institute at my college and this is some "homework" i got), and have no idea what those 2 terms mean. It's used in many places throughout.

 

EDIT: okay, I think more info is needed. The paper can be read here. It's not long. It's a study about human rhodopsin (visual pigment) mutations which lead to retinal diseases. Here's a couple examples of sentences using the phrase:

"For a given amino acid site, the average chemical severity of interspecific substitutions is a simple average of the severity of all ancestor-descendent amino acid differences throughout the tree."

and

"From a neutral theory perspective, the direction of difference in the chemical severity of disease mutations is expected, but the magnitude of this difference is not predicted by any existing theory."

 

Any shedding of light on this will be greatly appreciated

[Nashyboyo]

i think it basically means the consequence of that amino acid alteration. that's the only meaning i can get out of the context. the topic is on diseases associated with mutation so it would make sense, but i can't be sure.

[scicop]

i think it basically means the consequence of that amino acid alteration. that's the only meaning i can get out of the context. the topic is on diseases associated with mutation so it would make sense, but i can't be sure.

 

Thats correct. Basically its a "correalory substituted amino-acid evoluntion trace analysis" paper. The technique is to identify mutations (i.e. amino acid) in certain gene products and look for conservation/divergence of such mutation across species. This is an excellent method for structure function studies to hint at which amino acids are essential for protein function and, like in this paper, decifer the contribution of certain aa's for pathology.

 

Nature has a very nice way of conserving (or getting rid of) mutations that can be of relevance for protein function. In my studied field (receptor pharmacology) this technique (an in silico technique) is used by many to hypothesis essential amino acids for receptor function. Mutants can then be made based on this method and function can be assessed.

 

And they say that there is no evidence for evolution! Not to turn this into a evolution topic, simply opening a biology text book can do wonders for the intellectually inferior (i.e. holy bible believing morons).