The “Cystine-Cysteine Problem” was a phrase used in 1972 by chroniclers of the history of the discovery of the amino acids to describe the puzzle surrounding these two species, and how they are incorporated into proteins.1 Cysteine is the name given the monomeric amino acid with a free thiol group, whereas cystine is the name… Continue reading Cysteine (and Cystine)
Histidine
“In 1874 Miescher observed that a large proportion of the dry weight of the sperm of the Rhine salmon consisted of a ‘nuclein’” …a rather odd sentence that starts the section on histidine in Vickery and Schmidt’s 1931 history of the discovery of the amino acids.1 It really highlights just how odd chemistry was as… Continue reading Histidine
Alanine and Phenylalanine
Alanine was one of the few amino acids to be produced synthetically before it was discovered as part of proteins. It was first synthesised in 1850 by the German chemist Adolph Strecker, who was trying to make lactic acid from acetaldehyde, after Justus Liebig had shown the reverse reaction to be possible.1,2 He did manage… Continue reading Alanine and Phenylalanine
Amino Acid One-Letter Codes
Proteins structures are complicated (really complicated), and the code we use to describe their sequences needs to reflect this by being concise and easy to understand. As scientists became able to identify and synthesise longer and longer sequences of amino acids, the notation they used to characterise them had to adapt, evolve, and (crucially) condense.… Continue reading Amino Acid One-Letter Codes
Threonine, Threose, and Erythrose
Unlike essential oils, essential amino acids are a well named category of compounds. Referring to those that we are unable to make for ourselves and must be consumed in the diet, it was this property that was key to the discovery of the last of the twenty common amino acids: threonine. The Last Essential Amino… Continue reading Threonine, Threose, and Erythrose
Acetylene (and Hydrocarbon Suffixes)
In a previous post on this blog, I discussed the possibility for confusion among modern students of chemistry due to older, generic names of organic molecules being incongruous with the systematic naming conventions we use today. The example I used to make this point was acetone, which unlike acetic acid, acetylene, and acetaldehyde, contains three carbons… Continue reading Acetylene (and Hydrocarbon Suffixes)
Asparagine, Aspartate, Glutamine and Glutamate
There are four amino acids that are intrinsically linked by the similarity in their structures, and unsurprisingly, the stories behind their names are just as intertwined. I am of course referring to the compounds with the carboxylic acid and primary amide side chains: asparagine, aspartic acid, glutamine and glutamic acid. Asparagine Asparagine was the first… Continue reading Asparagine, Aspartate, Glutamine and Glutamate
Tryptophan(e)
The tale of tryptophan is a colourful one, quite literally. One of oldest texts we know of that is pertinent to this story dates back to 1825.1 It describes how the addition of dilute chlorine water to a preparation of pancreatic juices turned the liquid rose-red. If left to sit, violet flakes would appear after… Continue reading Tryptophan(e)
Amino Acids
“The discoverers of the amino acids are among the elite of science”. This statement was made in a 1931 review of the history of the discovery of the amino acids, and having read the stories of how each of these compounds came to be known, I cannot help but agree.1,2 Just from a technical perspective,… Continue reading Amino Acids
Systematic Nomenclature vs Common Names
Before I write too many of these posts, I thought it best to take a pause and talk a little bit about something that is going to come up a lot: the distinction between systematic nomenclature and common names, and the differing roles that they each play. A Shifting Attitude Towards Systematic Names As I’ve… Continue reading Systematic Nomenclature vs Common Names
