Understanding Serrapeptase Enzyme Activity – SPU, SU and IU
If have been searching the web for information about serrapeptase and other systemic enzyme supplements, you probably have run into the abbreviations SPU, SU and/or IU in relation to a serrapeptase product's potency. Since an enzyme's potency is the number one factor determining how well it works, understanding what these measurements mean and how they relate to each other is essential for being able to compare serrapeptase enzyme supplements, choose the most effective one and to take an effective serrapeptase dosage.
SPU (serratio peptidase units) and SU (serrapeptase units) are essential the same thing and can be used interchangeably (although SPU is generally used more often than SU). Both SPU and SU measure the activity or potency of the serrapeptase enzyme based on a specific scientific test. Therefore, SPU and SU are considered the 'active units' of serrapeptase. "S" represents Serrapeptase and "SP" represents Serratio Peptidase in this case, virtually 2 acronyms for the exact same enzyme. Since several enzymes begin with the letter S, SP has been adopted as the more common abbreviation for Serrapeptase.
Many companies use IU, or international units, when describing the activity of their serrapeptase enzyme supplements. However, international units (IU) are a completely different measurement than SPU or SU. An IU is defined as the quantity of a biologic substance (usually a vitamin or hormone) that produces a specific biological effect that has been agreed upon as an international standard. Despite its name, IU is not part of the International System of Units used in physics and chemistry. The IU should not be confused with the enzyme unit, also known as the International unit of enzyme activity and abbreviated as U.
Although IUs are a measure of potency, they can't be used to describe enzymes. This is because the method for measuring the potency of the serrapeptase enzyme and other enzymes isn't the same as measuring the potency of a vitamin. For serrapeptase it isn't the quantity (usually measured in milligrams or mg) that counts; rather it is the amount of fibrin or other proteins that serrapeptase can break down or digest that determines its potency.
All of this may seem a little technical, but here's the bottom line to clear any confusion you may have – the proper measurement for serrapeptase enzyme activity is SPU or SU since it is based on a test specifically designed for this enzyme. Any product or website stating that measurements listed in SPU and SU are considerably less potent than those measured in IU are completely false and misleading. Look for serrapeptase brands with higher SPU or SU to get a higher serrapeptase dosage.
- IU= Used for (vitamins and minerals) developed by Expert Committee on Biological Standardization is a functioning body of World Health Organization
- U= Used for enzymes developed by the International Union of Biochemistry and Molecular Biology (IUBMB)
Questions:
1) How does an IU compare to an SU?
Technically there is no International Units for enzymes, so you really cannot compare the two units of measure. Many companies assume that the SU denotes or equates to the international unit for Serrapeptase. So they blindly use the IU to denote SU. As confusing as this sounds basically most companies are mistakenly using IU instead of SU to rate their Serrapeptase product, thinking that they are the same measurement.
2) What is better an SU or an IU?
It's really hard to say. It is possible some companies think the SU is the international unit for Serrapeptase. In this case they would be the same. Since this is not the case, it is better to simply stay away from companies that do not know how to properly label their ingrediants.
Enzyme unit
The enzyme unit (U) is a unit for the amount of a particular enzyme.
One U is defined as the amount of the enzyme that catalyzes the conversion of 1 micro mole of substrate per minute. The conditions also have to be specified: one usually takes a temperature of 25°C[2] and the pH value and substrate concentration that yield the maximal substrate conversion rate.
The enzyme unit was adopted by the International Union of Biochemistry in 1964. Since the minute is not an SI unit, the enzyme unit is discouraged in favour of the katal, the unit recommended by the General Conference on Weights and Measures in 1978 and officially adopted in 1999. One katal is the amount of enzyme that converts 1 mole of substrate per second, so
- 1 U = 1/60 micro katal = 16.67 nano katal.
The enzyme unit should not be confused with the International Unit (IU), an unrelated measure of biologically active substances.