Hitachi Chemical

News Release

January 31, 2019
Kyowa Medex Co., Ltd.

Developing a New Enzyme that Can Shorten the Test Time
for Diagnosing Diabetes

Kyowa Medex Co., Ltd. (Head Office: Chuo-ku, Tokyo; President and COO: Toshihiro Onodera; hereinafter “Kyowa Medex”), a subsidiary of Hitachi Chemical Co., Ltd. (Head Office: Chiyoda-ku, Tokyo; President and CEO: Hisashi Maruyama), announces the development of hemoglobin A1c direct oxidase (hereinafter “HbA1cOX”), a new enzyme that can be applied to measurement reagents for hemoglobin A1c (hereinafter “HbA1c”)*1 used for diagnosing diabetes. This enzyme was created through collaborative research studies with Wataru Hashimoto, professor at the Kyoto University Graduate School of Agriculture, and Kousaku Murata, professor at the Setsunan University Faculty of Science and Engineering. The current HbA1c measurement adopts the method of using two types of enzyme reactions (two-step method), but this newly developed HbA1cOX for measurement reagents enables HbA1c to be measured by one type of enzyme reaction (one-step method) alone, with the measurement time expected to be shortened up to half that of the conventional method. Furthermore, HbA1cOX is the world’s first enzyme applicable to the one-step method.*2 Kyowa Medex will undertake the development of measurement reagents and devices with HbA1cOX to commercialize HbA1c measurement methods using this enzyme within three years.

*1
HbA1c is a protein formed by condensation of blood glucose and hemoglobin (Hb) in the blood, and HbA1c in the blood increases as the level of blood glucose becomes higher. Once formed, HbA1c remains in the blood for a certain period of time and its measurement can reflect medium- and long-term changes in blood glucose levels over a period of a few months.
*2
As of January 31, 2019. Based on Kyowa Medex’s own research.

The number of people in the world suffering from diabetes is increasing, with approximately 425 million people diagnosed with diabetes as of 2017, and the number is projected to climb to roughly 700 million by 2045.*3 HbA1c measurement has become a common way to diagnose diabetes because of its low cost and simplicity. HbA1c is measured via the oxidative reaction of enzyme called fructosyl peptide oxidase (hereinafter “FPOX”), but with large HbA1c molecules preventing HbA1c from directly reacting with FPOX, HbA1c needs to be decomposed by proteolytic enzyme as a pretreatment. The conventional solution requires a two-step method using decomposition reaction followed by oxidative reactions (see Chart 1).

*3
Source: The International Diabetes Federation (IDF), “Diabetes Atlas Eighth Edition 2017.”

To overcome this challenge, Kyowa Medex collaborated with Professors Hashimoto and Murata to develop the new “HbA1cOX” enzyme that can catalyze direct oxidative reaction with large HbA1c molecules by modifying the structure of a template enzyme owned by Kyowa Medex (see Chart 1). The HbA1c one-step method utilizing this new enzyme can eliminate the decomposition reaction process, possibly shortening the test time up to half that of the conventional method. Test costs can also be reduced because of the fewer types of enzymes required for measurement.

Kyowa Medex will utilize HbA1cOX to develop measurement reagents and devices and also to commercialize the HbA1c measurement methods, with the aim of helping patients and medical institutions reduce the various burdens involved in the prevention and diagnosis of diabetes.

Chart 1: Conventional measurement method (two-step method) and measurement method using a newly developed enzyme (one-step method)
Chart 1: Conventional measurement method (two-step method) and measurement method using a newly developed enzyme (one-step method)

Reference

Kyowa Medex and Professors Hashimoto and Murata submitted their research to the international scientific journal Scientific Reports and it was disclosed online on January 30, 2019(Japan time).