SUMITOMO RUBBER INDUSTRIES TOP > News > 2022 > Successful Experiment Opens the Door to Natural Rubber Bioengineering~Synthesizing Biopolymer Not Found in Nature~

Successful Experiment Opens the Door to Natural Rubber Bioengineering~Synthesizing Biopolymer Not Found in Nature~

 Sumitomo Rubber Industries, Ltd. is pleased to announce that, through joint research undertaken with Associate Professor Seiji Takahashi of Tohoku University, Associate Professor Satoshi Yamashita of Kanazawa University and Professor Yuzuru Tozawa of Saitama University, we have identified the segment of natural rubber synthase that plays an important role in controlling natural rubber polymer chain lengths. Further, by recombining this important segment for controlling natural rubber polymer chain lengths with an enzyme derived from tomatoes, we have now succeeded in synthesizing a biopolymer that features a structure not found in nature. Moving forward, we will continue this line of research in the hope that it will lead to improved natural rubber yields as well as the creation of new strains of natural rubber that will contribute to improvements in overall tire performance.


Through our research, we succeeded in discovering the important segment that affects chain length by comparing the structures of the enzymes involved in the synthesis of natural rubber (i.e. long chains) with the structures of the enzymes involved in isoprene chain synthesis of tomatoes (i.e. short chains), as both of these enzymes belong to the same enzyme group and share similar structures.

Further, we also found that replacing this important segment of the tomato enzyme with the same segment from the natural rubber synthase resulted in a modified enzyme that synthesized polyisoprene with chain lengths comparable to natural rubber. The use of this modified enzyme allowed us to utilize a starting substrate that is unlike natural rubber synthase in order to successfully synthesize a biopolymer not found in nature as the product of the resulting synthesis reactions.

Tomato Enzyme Natural Rubber Synthase
Important Segment Affecting Chain Length Outlined in Red

Image Illustrating Replacement of Important Segment

Image of Synthesis Reactions Using Enzymes as Catalysts

① Normal Synthesis of Natural Rubber  ② Tomato Enzyme Only Able to Synthesize Short Chains

③ By using the modified enzyme as a catalyst, we succeeded in synthesizing a biopolymer that, while having a structure unlike natural rubber, nevertheless features a chain length that is comparable to natural rubber.


We recently announced the results of our research at the DKT IRC 2021*1 expo and conference, which was held this past June 27th through 30th in Nuremburg, Germany. Moving forward, the Sumitomo Rubber Group will continue working to contribute to the realization and prosperity of a sustainable society through our ongoing efforts to ensure a stable supply of natural rubber while providing tires that combine safety and peace of mind with reduced environmental impact.

※1. DKT IRC is an international expo and conference featuring presentations on a wide range of themes relating to rubber technology. (DKT IRC 2021 was held in 2022 due to the pandemic.)

DKT IRC 2021 Homepage:



■Previous News Releases

Elucidating the Structure of Tomato Enzymes (Similar to Natural Rubber Synthases) (Issued March 3, 2022)

“SRI Reports on the Results of Research on the Mechanisms behind the Biosynthesis of Natural Rubber in Pará Rubber Trees” (Issued October 26, 2016)