science

Latisemin

Latisemin is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Latisemin rather than just read about it. In short: Latisemin is a cysteine-rich secretory protein that can be isolated from the venom of the Black-banded sea krait, a sea snake indigenous to the warmer waters of the western Pacific Ocean. It is a toxin that inhibits cyclic nucleotide-gated ion channels and blocks L-type calcium channels, thereby reducing smooth muscle contraction.

Key takeaways

Latisemin belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Latisemin to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Latisemin from memory before moving on to harder problems.

Reference excerpt

Latisemin is a cysteine-rich secretory protein that can be isolated from the venom of the Black-banded sea krait, a sea snake indigenous to the warmer waters of the western Pacific Ocean. It is a toxin that inhibits cyclic nucleotide-gated ion channels and blocks L-type calcium channels, thereby reducing smooth muscle contraction.

Sources

Latisemin is a component of the venom produced by the Erabu sea snake (Laticauda semifasciata) of the family Elapidae and the Laticauda genus. These sea snakes inhabit coral reef areas in the seas of Southern Japan, Southeast Asia, and Australia. Though highly venomous, this snake is comparatively unaggressive, and is in fact caught and eaten in Erabu soup in Japan.

Biochemistry Latisemin has a molecular weight of 24 kDa and consists of 217 amino acids. It belongs to the CRISP (cysteine-rich secretory protein) glycoprotein subfamily, which are single chain polypeptides containing strictly conserved cysteines (cysteines not oxidised to cystine and thus not providing disulfide bond support to tertiary protein structure). They are secretory proteins, meaning they are secreted from cells into extracellular fluid.

Target Latisemin strongly blocks depolarization- (but not caffeine-) induced smooth muscle contraction, suggesting that it blocks L-type calcium channels. Its mode of action is similar to that of some other snake venom toxins from the CRISP family, like ablomin from the Japanese Mamushi snake and triflin from the Habu snake. They also inhibit cyclic nucleotide-gated ion channels.

See also Other snake venom proteins in the CRISP family:

Ablomin from the Japanese Mamushi snake (Gloydius blomhoffii) Ophanin from the King Cobra (Ophiophagus hannah) Piscivorin from the Eastern Cottonmouth (Agkistrodon piscivorus) Triflin from the Habu snake (Trimeresurus flavoviridis)

References

Worked examples

Example 1 — a first encounter with Latisemin

Start with the simplest possible case. Write down what Latisemin claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Latisemin before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Latisemin ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Latisemin

In research: Latisemin appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Latisemin in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Latisemin is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ion channel toxins, Snake toxins, so understanding it makes those chapters shorter.
In everyday life: Look for Latisemin outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Latisemin in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Latisemin means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Latisemin out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Latisemin in simple terms?

Why does Latisemin matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Latisemin?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Latisemin.