Talk:Luciferase

References to energy efficiency broken

I could not access any of the two references (numbered 11 and 12) on the energy efficiency of the light reaction. Benjamin.friedrich (talk)

Energy of light reaction

It would be nice to state the energy balance of the light-reaction in absolute terms. Since the chemical potential of one ATP molecule is about 1e-19 J=25 kBT [Howard:Mechanics of Motor Proteins, Sinauer:2001], and a photon has an energy of 75 kBT (red light) Photon energy, at least 4 (if not more) ATP would be needed to get the luciferin in the excited state. Does anybody has expert knowledge to confirm this? Benjamin.friedrich (talk)

Chemical compound

Luciferase is an enzyme and not a chemical compound. --User:AAM | Talk 17:12, 18 April 2006 (UTC)

What part of the definition of a chemical compound does enzyme not fit? --Blainster 21:40, 18 April 2006 (UTC)

"A defining characteristic of a compound is that it has a chemical formula. Formulas describe the ratio of atoms in a substance, and the number of atoms in a single molecule of the substance (thus the formula for ethene is C2H4 rather than CH2). The formula does not indicate that a compound is composed of molecules; for example, sodium chloride (table salt, NaCl) is an ionic compound."

Enzymes do not have a fixed chemical formula, they have variable phosphorylations, ubiquitinations, sumoylations, glycosylations, myristylations etcetera. Does this convince you enough? --User:AAM | Talk 22:03, 18 April 2006 (UTC)

I agree - there are multiple forms of Luciferase - see Category:EC 1.13.12. A singly isolated luciferase could be described as a compound, but as a class of enzymes, they would best be described as a class of compounds.--Scienthomas 03:34, 19 April 2006 (UTC)

Any particular instance of an enzyme is, in fact, a chemical compound that "has a chemical formula". but I can agree with Scienthomas that an enzyme, more broadly taken, is a group or class of chemical compounds. To say an enzyme is not a chemical compound is like saying you are not made up of atoms because you are made of molecules. --Blainster 20:19, 19 April 2006 (UTC)

Would you argue that we ourselves should be classified as a group or class of chemical compounds as well, as we are composed of atoms? If we continue on that line then everything except a vacuum might classify as a chemical compound. --User:AAM | Talk 20:42, 19 April 2006 (UTC)

Here is another one: "A chemical compound is a chemical substance formed from two or more elements, with a fixed ratio determining the composition". Enzymes have definitely not a fixed ratio. Enzymes are classified by their EC numbers, not by a chemical formula --User:AAM | Talk 20:42, 19 April 2006 (UTC)

What is meant by saying fixed ratio, is to include the subset of polymers which do not have well defined MWs but do have a fixed ratio of elements. Of course enzymes are a type of "polymeric" compound that do have fixed MWs (assuming unbound substrates, subunits, etc). So we have compound -> polymer -> protein -> enzyme as increasingly specialized subsets of the class. Humans are clearly a mixture of various chemical compounds, but not a class because our diverse compounds are in the most general sense related more by proximity than by composition. To answer your question of how broadly to conceive chemical compounds, we can be much more specific than "everything except a vacuum". Plasmas certainly wouldn't qualify. To be a bit more serious, the salient points are: a compound is made up of 1) more than one element, and 2) with fixed ratio rather than amorphous composition. Proteins and enzymes satisfy both conditions. --Blainster 21:54, 19 April 2006 (UTC)

I forget about plasmas! But I insist that an enzyme has no fixed ratio as I said above. Without taking into account substrates (that are but for some exceptions only transiently associated anyway) and subunits, most enzymes, if not all, are variably modified (phosphate groups, ubiquitine groups, acetyl groups, methyl groups) and this makes that the ratio of elements varies. The Mw of a protein can also change in fonction of these modifications (do you want me to find an illustrating picture of this?). It would be interesting to 'find' the chemical formula of luciferase, then we could find out how this changes after some of the above mentioned modifications :-) --User:AAM | Talk 18:31, 20 April 2006 (UTC)

(an analog of muscle contraction)

Is this appropriate? ATP and calcium play a role in muscle contraction, but that doesn't make it an analogy. neffk 14:08, 5 September 2006 (UTC)

Indeed this part is very strange and does not give relevant information in my opinion. I removed the entire part, also on the Ca ions. Could the Ca ion part be substantiated by a reference than we can put it back. I do not know such reference. --User:AAM | Talk 18:08, 6 September 2006 (UTC)

The bioluminescent reaction between the luciferin complex, luciferase and oxygen is triggered by calcium ions. [1], and literature references therein. Journal discussions cite the muscle analogy. --Blainster 20:06, 6 September 2006 (UTC)

OK Renilla luciferase is catalyzed by Ca according to the literature. I think this should be specified in the text, as each luciferase and luciferin can have different caracteristics. Now it suggests that all luciferases are triggered by calcium and I don't think there is information on that. The mentioning of the analogy with muscle contraction sounds strange. The way it stands it sounds as if the chemical luciferase reaction is analogous to a contraction of a muscle, I agree with neffk that this seems not appropriate as analogy. Maybe a rewording could clarify this point if something more specific is meant? Perhaps than the exact reference for the muscle contraction could be mentioned in the text as well, this is not the case at this moment which makes it difficult to keep this information in the article. --User:AAM | Talk 20:18, 11 September 2006 (UTC)

Renilla luciferase is definitely NOT catalyzed by calcium, I've edited the page to add a little more info on renilla luciferase and to clarify things. There's a protein that binds the luciferin that is triggered to release the substrate by calcium. I'd also like to think the muscle analogy is strange... could somebody explain it? loening (talk) 21:42, 28 November 2008 (UTC)

Heat-shock

Luciferase is a very heat sensitive protein that is used in studies on protein denaturation, testing the protective capacities of heat shock proteins.

Okay, I'm going to preface this by saying I know, at best, a little more than the average person about biology, chemistry, and physics, so maybe this is just my stupidity. That said, as joe shmoe reading an encyclopedic entry, this statement is unclear to me. I have skimmed the sections on both heat-shock and denaturation, and it's unclear to me what is meant by the statement "very heat sensitive." Certainly, it means that Luciferase react in some extreme way to heat. But it's unclear to me whether that means that it reacts by heat killing it off, or to heat by causing it to multiply, or something else entirely. (I'm inclined to believe the first option, but...) Clarification would be great.--Sailor Titan (talk) 22:34, 5 February 2008 (UTC)

Lucifer

There should be some talk on why the name of Lucifer has been adopted for bioluminescence. The most obvious reason is that Lucifer means Morning Star, popularised by the KJ version of the Vulgate Bible translated at Isaiah 14:12. (Vesper means night star.) For some reason, Christians traditionally thought this was Satan, even though it clearly means Venus. A Freemason called Pike, around 1849 thought he would annoy Christians by showing how ignorant they were. In jest, he said he aspired to the principle of Lucifer (intellectual illumination, in his mind), whereupon he and his Freemason kind were howled down as Satan worshippers. It's most likely that the chemist who named these enzymes with the root Lucifer was also having a reprise jibe at ignoramuses. If he was using real Latin, it would be Lux or Lucis Bipedia (talk) 15:14, 1 September 2008 (UTC)

references

I moved the references Baldwin and Greer to the external links since these references were not indicated in the text. Since the references are not publically available I could not put reference at the right place in the text. Hopefully the person who used them for the preparation of the text can put them at the right place
E.J.Hoekstra (talk) 20:39, 16 September 2008 (UTC)

Merge proposal

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result was no merge -- Rob T Firefly (talk) 10:38, 2 July 2009 (UTC)

---

I think this article should be merged with luciferin. Both articles essentially describes the same reaction, and besides, neither of the articles is long enough to justify having an own article. Mikael Häggström (talk) 17:36, 6 March 2009 (UTC)

Oppose. Luciferase is a fairly broad class enzymes expressed in wide variety of organisms from bacteria to insects to fish while luciferin is an equally diverse class of small molecules heterocycles which are the substrates of the enzyme. Given the dissimilarity of the subject matter (protein vs. small molecule) and the breadth of the topics, each subject deserves its own article and both articles could easily be expanded. Boghog2 (talk) 18:37, 6 March 2009 (UTC)

Also oppose. They serve very different functions and have different properties, so it would be confusing to join them together. beroe (talk) 20:05, 30 March 2009 (UTC)

Oppose. They are very different subjects. Rob T Firefly (talk) 16:20, 29 June 2009 (UTC)

Given the elapsed time and consensus, I'm going to go ahead and remove the merge tags. Rob T Firefly (talk) 19:39, 30 June 2009 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Luciferase applications confused with those of luminol

The wikipedia article currently says, "Luciferase can be used in blood banks to determine if red blood cells are starting to break down. Forensic investigators can use a dilute solution containing the enzyme to uncover traces of blood remaining on surfaces at a crime scene." These applications are not among those listed in the source cited (Massoud TF, Paulmurugan R, De A, Ray P, Gambhir SS (February 2007). "Reporter gene imaging of protein-protein interactions in living subjects". Curr. Opin. Biotechnol. 18 (1): 31–7). These are applications of luminol, a non-protein, organic compound. [[2]] I believe the article has confused luciferase and luminol with regards to these applications. Unless a suitable source can be found saying luciferase is used in forensic detection of blood, the mention of this application should be deleted from the article. —Preceding unsigned comment added by 169.234.137.251 (talk) 19:55, 15 January 2010 (UTC)

As luciferase requires ATP and magnesium to function, it is typically used to detect the presence of ATP. This may not be so useful in forensics, but for detecting the presence of life, cells in general, etc. Wrfrancis (talk) 20:45, 23 June 2010 (UTC)

I have to second the opinion above. I, too, question the validity of the use of luciferase in detecting blood. It might be able to be used by some complicated or expensive method, but it is my understanding that luminol is the correct term meant for the article. If anyone can substantiate the use of luciferase for these purposes, I would insist that references be posted; else the section should be revised. (I also checked the reference listed, which was unrelated.) Jdevola (talk) 01:06, 21 March 2013 (UTC)

I agree. The citation does not support the use of luciferase in forensics or blood banks, nor can I find any evidence of these. I am concerned that these claims are already being copied verbatim in other websites. I will delete the claims accordingly. Note: I am a PhD in Entomology with experience in research. 76.105.6.149 (talk) 09:26, 19 June 2014 (UTC)

Bacterial vs Firefly

I move that bacterial luciferase and firefly luciferase be separated into distinct articles.

They have different substrates, different kinetics, different species of origin...I think it is confusing to include both in the same article. — Preceding unsigned comment added by 193.174.111.250 (talk) 15:48, 27 June 2013 (UTC)

Application in DNA sequencing

As far as I know, luciferase is an important component in some of the new generation DNA sequencing methods (pyrosequencing). Kenadra (talk) 10:13, 18 June 2014 (UTC)

Too much firefly

Luciferase is a general class of enzymes. The content is too heavily based on firefly luciferase and should be split into two or more articles. Wrfrancis (talk) 13:56, 29 October 2014 (UTC)

If this is necessary for more detailed treatment of firefly, dinoflagellate and bacterial luciferases, so be it, but we should definitely have a top-level article on luciferases in general: though I wonder if even that isn't a somewhat misleadingly specialized title, as there are other enzymes in the shape of photoproteins like aequorin which would be best discussed along with luciferases (narrowly understood) as 'light-generating enzymes'. Shame that history forbids us from calling all of those proteins 'luciferases'. Chiswick Chap (talk) 12:04, 28 November 2014 (UTC)

Very Poorly Written Article

As is the case with most technical or scientific WP articles in recent memory, this one is terribly written, presumably by experts in the subject matter, but lacking in writing skills. Writing is normally used to communicate ideas. This article fails to achieve that goal for 99% of the people who attempt to read it. It is overloaded with jargon, and reads like segments of a very poor textbook. I hope that everyone who contributed enjoys the temporary ego boost, because Yea Verily, that is all that was achieved. 98.194.39.86 (talk) 07:00, 16 December 2016 (UTC)

Wikipedia is citing Snopes now?

How low we’ve fallen. —NoApostropheInIts (talk) 18:10, 8 November 2021 (UTC)

Well, it certainly isn't my go-to source, but WP:SNOPES is green, and it adequately presents verifiable facts supplemented with a Reuters reference. soibangla (talk) 18:33, 8 November 2021 (UTC)

weird reference to quantum dots

I find the reference at the beginning of the article very far-fetched (and at best only relevant to a very specific use of these enzymes). If it is considered relevant to point out the relation to this record keeping technique, wouldn't it make more sense to do so in an explanatory paragraph (with suitable citations) further down in the article? As is, it seems to me an overly prominent place to make a rather tenuous connection. --Qcomp (talk) 11:06, 16 June 2022 (UTC)