Hyaluronidase

Key takeaways

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

Reference excerpt

Hyaluronidases are a family of enzymes that catalyse the degradation of hyaluronic acid. Karl Meyer classified these enzymes in 1971, into three distinct groups, a scheme based on the enzyme reaction products. The three main types of hyaluronidases are two classes of eukaryotic endoglycosidase hydrolases and a prokaryotic lyase-type of glycosidase. In humans, there are five functional hyaluronidases: HYAL1, HYAL2, HYAL3, HYAL4 and HYAL5 (also known as SPAM1 or PH-20); plus a pseudogene, HYAL6 (also known as HYALP1). The genes for HYAL1-3 are clustered in chromosome 3, while HYAL4-6 are clustered in chromosome 7. HYAL1 and HYAL2 are the major hyaluronidases in most tissues. GPI-anchored HYAL2 is responsible for cleaving high-molecular weight hyaluronic acid, which is mostly bound to the CD44 receptor. The resulting hyaluronic acid fragments of variable size are then further hydrolyzed by HYAL1 after being internalized into endo-lysosomes; this generates hyaluronic acid oligosaccharides. Hyaluronidases are hyaluronoglucosidases (EC 3.2.1.35), i.e. they cleave the (1→4)-linkages between N-acetylglucosamine and glucuronate. The term hyaluronidase may also refer to hyaluronoglucuronidases (EC 3.2.1.36), which cleave (1→3)-linkages. In addition, bacterial hyaluronate lyases (EC 4.2.2.1) may also be referred to as hyaluronidases, although this is uncommon.

Use as a drug

Medical uses By catalyzing the hydrolysis of hyaluronan, a constituent of the extracellular matrix, hyaluronidase lowers the viscosity of hyaluronan, thereby increasing tissue permeability. It is, therefore, used in medicine in conjunction with other drugs to speed their dispersion and delivery. Common applications are ophthalmic surgery, in combination with local anesthetics. It also increases the absorption rate of parenteral fluids given by hypodermoclysis, and is an adjunct in subcutaneous urography for improving resorption of radiopaque agents. Hyaluronidase is also used for extravasation of hyperosmolar solutions. Besides, hyaluronidase is a recommended antidote for vinca alkaloid overdose or extravasation. Hyaluronidase can be injected to dissolve hyaluronic acid type dermal fillers and is the best treatment option for those looking at dissolving lip filler or dealing with related complications.

Purified and recombinant hyaluronidases Four different purified hyaluronidases have been approved for use in the United States, three of animal origin and one recombinant. They are indicated as adjuvants in subcutaneous fluid administration for achieving hydration, for increasing the dispersion and absorption of other injected drugs, or for improving resorption of radiopaque agents, in subcutaneous urography. The three naturally-sourced hyaluronidases are orthologs of human HYAL5 (PH20) obtained from testicular preparations. They are sold under the brand names Vitrase (ovine, FDA-approved in May 2004), Amphadase (bovine, October 2004) and Hydase (bovine, October 2005). Human recombinant hyaluronidase (Hylenex Recombinant)—approved for use in the United States in December 2005—corresponds to the soluble fragment of human HYAL5 (PH20) produced in culture by genetically engineered Chinese hamster ovary cells containing a DNA plasmid encoding the enzyme.

Combination treatments A human recombinant hyaluronidase kit, Hyqvia, was approved for use in the European Union in May 2013, and in the United States in September 2014. It is a dual vial unit with one vial of immune globulin infusion 10% (human) and one vial of recombinant human hyaluronidase. It is an immune globulin with a recombinant human hyaluronidase indicated in the United States for the treatment of primary immunodeficiency in adults. This includes, but is not limited to, common variable immunodeficiency, X-linked agammaglobulinemia, congenital agammaglobulinemia, Wiskott-Aldrich syndrome, and severe combined immunodeficiencies. In the European Union it is indicated as replacement therapy in adults, children and adolescents (0–18 years) in:

Primary immunodeficiency syndromes with impaired antibody production. Hypogammaglobulinaemia and recurrent bacterial infections in patients with chronic lymphocytic leukaemia, in whom prophylactic antibiotics have failed or are contra‑indicated. Hypogammaglobulinaemia and recurrent bacterial infections in multiple myeloma (MM) patients. Hypogammaglobulinaemia in patients pre‑ and post‑allogeneic hematopoietic stem cell transplantation. A form of subcutaneous immunoglobulin (SCIG) that uses Hylenex to allow for a far greater volume of SCIG to be administered than would normally be possible to administer subcutaneously, providing a form of SCIG that can be dosed on a monthly basis, a longer period of time than other forms of SCIG allow. HyQvia had a rate of systemic adverse effects higher than traditional subcutaneous forms of immunoglobulin injection, but lower than those typical in IVIG patients. Hyaluronidase is available in some fixed-dose combination drug products in the United States: rituximab/hyaluronidase (Rituxan Hycela), trastuzumab/hyaluronidase-oysk (Herceptin Hylecta), daratumumab/hyaluronidase-fihj (Darzalex Faspro), pertuzumab/trastuzumab/hyaluronidase–zzxf (Phesgo). In July 2021, the US Food and Drug Administration (FDA) approved daratumumab and hyaluronidase-fihj in combination with pomalidomide and dexamethasone for adults with multiple myeloma who have received at least one prior line of therapy including lenalidomide and a proteasome inhibitor. Efgartigimod alfa/hyaluronidase (Vyvgart Hytrulo) was approved for the treatment of generalized myasthenia gravis in the United States in June 2023. Ocrelizumab/hyaluronidase (Ocrevus Zunovo) was approved for medical use in the United States in September 2024. Atezolizumab/hyaluronidase (Tecentriq Hybreza) was approved for medical use in the United States in September 2024. Nivolumab/hyaluronidase (Opdivo Qvantig) was approved for medical use in the United States in December 2024. In October 2025, the US Food and Drug Administration approved a combination of atezolizumab, hyaluronidase, and lurbinectedin for the treatment of adults with extensive-stage small cell lung cancer. Amivantamab/hyaluronidase (Rybrevant Faspro) was approved for medical use in the United States in December 2025.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Hyaluronidase

Start with the simplest possible case. Write down what Hyaluronidase claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 Hyaluronidase 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 Hyaluronidase 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 Hyaluronidase

In research: Hyaluronidase appears in biology 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 Hyaluronidase 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: Hyaluronidase is common in secondary-school and first-year university syllabi. It links to neighbouring topics EC 3.2.1, Extracellular matrix remodeling enzymes, so understanding it makes those chapters shorter.
In everyday life: Look for Hyaluronidase 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.

How to study Hyaluronidase in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Hyaluronidase 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 Hyaluronidase out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Hyaluronidase in simple terms?

Hyaluronidases are a family of enzymes that catalyse the degradation of hyaluronic acid. Karl Meyer classified these enzymes in 1971, into three distinct groups, a scheme based on the enzyme reaction products.

Why does Hyaluronidase matter?

Because it connects several biology 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 Hyaluronidase?

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 Hyaluronidase.