LAB Chemistry - file 01
The Longest Name of Matter – the Protein Titin
Methionylthreonylthreonylglutaminylalanylprolylthreonylphenylalanylthreonylglutaminylprolylleucylglutaminylserylvalylvalylvalylleucylglutamylglycylserylthreonylalanylthreonylphenylalanylglutamylalanylhistidylisoleucylserylglycylphenylalanylprolylvalylprolylglutamylvalylseryltryptophylphenylalanylarginylaspartylglycylglutaminylvalylisoleucylserylthreonylserylthreonylleucylprolylglycylvalylglutaminylisoleucylserylphenylalanylserylaspartylglycylarginylalanyllysylleucylthreonylisoleucylprolylalanylvalylthreonyllysylalanylasparaginylserylglycylarginyltyrosylserylleucyllysylalanylthreonylasparaginylglycylserylglycylglutaminylalanylthreonylserylthreonylalanylglutamylleucylleucylvalyllysylalanylglutamylthreonylalanylprolylprolylasparaginylphenylalanylvalylglutaminylarginylleucylglutaminylserylmethionylthreonylvalylarginylglutaminylglycylserylglutaminylvalylarginylleucylglutaminylvalylarginylvalylthreonylglycylisoleucylprolylasparaginylprolylvalylvalyllysylphenylalanyltyrosylarginylaspartylglycylalanylglutamylisoleucylglutaminylserylserylleucylaspartylphenylalanylglutaminylisoleucylserylglutaminylglutamylglycylaspartylleucyltyrosylserylleucylleucylisoleucylalanylglutamylalanyltyrosylprolylglutamylaspartylserylglycylthreonyltyrosylserylvalylasparaginylalanylthreonylasparaginylserylvalylglycylarginylalanylthreonylserylthreonylalanylglutamylleucylleucylvalylglutaminylglycylglutamylglutamylglutamylvalylprolylalanyllysyllysylthreonyllysylthreonylisoleucylvalylserylthreonylalanylglutaminylisoleucylserylglutamylserylarginylglutaminylthreonylarginylisoleucylglutamyllysyllysylisoleucylglutamylalanylhistidylphenylalanylaspartylalanylarginylserylisoleucylalanylthreonylvalylglutamylmethionylvalylisoleucylaspartylglycylalanylalanylglycylglutaminylglutaminylleucylprolylhistidyllysylthreonylprolylprolylarginylisoleucylprolylprolyllysylprolyllysylserylarginylserylprolylthreonylprolylprolylserylisoleucylalanylalanyllysylalanylglutaminylleucylalanylarginylglutaminylglutaminylserylprolylserylprolylisoleucylarginylhistidylserylprolylserylprolylvalylarginylhistidylvalylarginylalanylprolylthreonylprolylserylprolylvalylarginylserylvalylserylprolylalanylalanylarginylisoleucylserylthreonylserylprolylisoleucylarginylserylvalylarginylserylprolylleucylleucylmethionylarginyllysylthreonylglutaminylalanylserylthreonylvalylalanylthreonylglycylprolylglutamylvalylprolylprolylprolyltryptophyllysylglutaminylglutamylglycyltyrosylvalylalanylserylserylserylglutamylalanylglutamylmethionylarginylglutamylthreonylthreonylleucylthreonylthreonylserylthreonylglutaminylisoleucylarginylthreonylglutamylglutamyl…… (2974 characters)
Well, I’m sorry… It’s been so long that I finally can’t copy and paste with the system frozen… These letters are NOT random. This is the chemical name of a protein commonly called “Titin,” also known as connectin. It is also known as the longest word in the English language, consisting of 189,819 letters. So the beginning part of the full name that I copied above is ONLY 1.57% (2974 characters)!
Titin has the longest IUPAC (the International Union of Pure and Applied Chemistry) name of a protein. The full chemical name of Titin denotes a series of amino acids, and boasts to be the longest word in the English language, and NO doubt, in any other languages. However, lexicographers regard a formal name of chemical compounds as “verbal formulae” rather than English words.
System Failure,... Dictionaries Reject,...
In etymology, the name Titin is derived from the Greek giant deity, Titan, which signifies anything of great size.
Titin’s full chemical name begins with "Methionyl..." and ends with "...isoleucine," frequently seen connected with ‘—nyl’ or ‘—yl.’ If the full name is written out in standard font, the immense length would fill approximately 57 pages!
And if reading the entire name of Titin aloud, the time to pronounce it would take roughly 3.5 hours!
As I experienced, most word processors, text boxes, or websites have their own character limits, often between 5,000 and 50,000 characters. Those system limitations are far shorter than the nearly 190,000 characters of the full chemical name of Titin to contain it…
Although I tried to copy the full chemical name of Titin into a text editor, the software froze and crashed, refusing to paste it… The clipboard manager might possibly consider the full name of Titin a bug or an invalid operation…
The word (if regarded) is too long because it lists the entire amino acid sequence of the largest known protein, which has 34,350 amino acids! Titin really exists, nevertheless, it is NOT listed in standard dictionaries…
Dictionaries reject Titin?
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| The Oxford English Dictionary (OED) 2nd edition |
The World’s most comprehensive and authoritative English dictionary is NO doubt the Oxford English Dictionary (OED).
The second edition of the Oxford English Dictionary (OED), published in 1989, comprises 20 volumes, printed in 21,730 pages in total! The 20-Volume Second Edition (OED2) covers 291,500 main entries, and approximately 615,100 word-forms defined or illustrated in total, with 888,251 meanings, and 3,927,862 quotations!
The Oxford English Dictionary (OED) does NOT contain the full chemical name for Titin. It is to be said as the longest ‘word’ in the English language, Titin's chemical name is regarded as a technical chemical formula rather than a recognized dictionary word.
Lexicographers consider the 189,819-letter long string of Titin a verbal formula or technical chemical nomenclature rather than a word, as it is impractical for communication, taking 3.5 hours to pronounce...
Actually, the longest word found in the Oxford English Dictionary (OED) is said…
pneumonoultramicroscopicsilicovolcanoconiosis
This 45-letter word means the name of a lung disease caused by inhaling very fine ash and sand dust.
What is the Protein Titin?
Titin (also known as connectin) is the largest known protein in the human body. Titins exist in our striated muscles, exclusively in skeletal muscles and heart (or cardiac) muscles and play a crucial role as a molecular spring to contract and relax those muscles.
Titin spans half the length of a Sarcomere and provides structural integrity, generating passive tension to support muscle contraction.
How do our skeletal muscles contract? – Sarcomere
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| Sarcomere (source: Physiopedia, the Journal of Clinical Investigation) |
Let’s take a look at this diagram inside of the myofibril in a Muscle Fiber above (source: Physiopedia, the Journal of Clinical Investigation)! The right shows How a muscle contracts.
A Sarcomere is the smallest functional unit of muscle contraction in the myofibrils of skeletal muscles and heart (cardiac) muscles. In a Sarcomere, there are two kinds of filaments, Myosin (thick filament) and Actin (thin filament), which are arranged in parallel, alternating rows and slide past one another during contraction. And the Sarcomere features the structures consisting of Z-disk (or Z-line), M-band (or M-line), I-band, H-zone (or H-band), and A-band, which designate specific zones in a unit of Sarcomere, respectively.
As the right diagram depicts, when muscle contraction occurs, Myosin (thick filaments) pulls Actin (thin filaments) toward the M-band (center of the Sarcomere), causing the entire Sarcomere to shrink along the direction of filaments.
So when our skeletal muscles or heart (cardiac) muscles contract and relax, the length of these units, the Sarcomeres themselves, is shortened and reverted. Sarcomeres exhibit maximum tension when their length is in the range of approximately 2.25 to 2.7 micrometers (μm = 0.001 mm).
Titin is the primary molecular spring in striated muscles, acting as a giant elastic protein spanning from the Z-disk (both ends of the Sarcomere) toward the M-band (center of the Sarcomere) within the Sarcomere. During the process of muscle contraction, Titin generates passive tension, maintains structural integrity, and contributes to Sarcomere elasticity.
The largest protein – Titin
Titin boasts a massive structure as the largest single polypeptide chain. While the number of amino acids that Titin contains depends on the isoform (variant of protein) and species, the human canonical isoform is said to contain 34,350 amino acids. Titin is far larger than typical proteins, which usually contain a few hundred amino acids.
Titin’s polypeptide chain runs from the Z-disk (both ends of the Sarcomere) to the M-band (the center of the Sarcomere) within the Sarcomere. I guess that’s probably why Titin is also called “Connectin.” And in the I-band region (outer zone across two adjacent Sarcomeres; see the diagram above!), Titin acts as an elastic spring that stretches during muscle extension and recoils during contraction. This is called the Molecular Spring in biology and biophysics, which is a crucial mechanism for passive muscle force.
Titin is often considered the 3rd most abundant protein in muscle tissue, following Myosin (thick filaments) and Actin (thin filaments). During muscle development, Titin functions as a protein ruler that helps organize and assemble the myofibrils, both Myosin (thick filaments) and Actin (thin filaments).
And it’s also known that Mutations in the TTN gene, which encodes for Titin, are associated with various cardiovascular and skeletal muscle diseases, such as dilated cardiomyopathy (DCM) and various myopathies.
If you are interested in the FULL chemical name of Titin, visit Wiktionary:
https://en.wiktionary.org/wiki/Appendix:Protologisms/Long_words/Titin#Noun
Don't worry, it's NOT as long as the mathematical constant “π”(Pi)...
Further reading (sponsored by Amazon):
● Jonathan Law (editor), et al.(2020). A Dictionary of Chemistry (8th edition; Oxford Quick Reference). 640 pages. Oxford University Press.
“A Dictionary of Chemistry”(Oxford Quick Reference)
(sponsored by Amazon)
“A Dictionary of Chemistry”(Oxford Quick Reference) is a popular and authoritative guide to ALL aspects of chemistry! With over 5,000 entries, “A Dictionary of Chemistry”(Oxford Quick Reference) boasts its broad coverage, including physical chemistry and biochemistry, and is heavily informed by the most current research! I’m sorry I couldn’t find Titin’s full chemical name in this “A Dictionary of Chemistry”(Oxford Quick Reference) though...
Table of Contents
Alphabetical List of EntriesPreface
DictionaryA – Z
Atomic Theory ChronologyBiochemistry ChronologyCrystal Defects (Feature)Explosives ChronologyPlastics ChronologyPolymers (Feature)
Appendices1: The Greek alphabet2: Fundamental constants3: SI units4: The electromagnetic spectrum5: The periodic table6: The chemical elements7: Nobel prizes in chemistry
8: Useful websites
“A Dictionary of Chemistry”(Oxford Quick Reference)
(sponsored by Amazon)
“A Dictionary of Chemistry”(Oxford Quick Reference) is a popular and authoritative guide to ALL aspects of chemistry! With over 5,000 entries, “A Dictionary of Chemistry”(Oxford Quick Reference) boasts its broad coverage, including physical chemistry and biochemistry, and is heavily informed by the most current research! I’m sorry I couldn’t find Titin’s full chemical name in this “A Dictionary of Chemistry”(Oxford Quick Reference) though...
