The active Ni(II) centre of metalloenzyme urease forms a coordination with substrate urea prior to the hydrolysis of urea. The present study provided the direct experimental evidences of isotope preferential coordination between Ni(II) metal centre of urease enzyme and substrate urea, which eventually alters the product yield. Furthermore, in-vitro experiments revealed that the specific ¹²CO₂ isotopic species bridges between heavier isotope of substrate urea [¹³CO(NH₂)₂] and Ni(II) centre of urease for more effective coordination, which ultimately enhances the yield of the reaction. Finally, the in-vitro observations have been validated under in-vivo physiological conditions exploiting the urease activity of the gastric pathogen Helicobacter pylori present in human stomach. Hence, the present study paves the way for better understanding of the isotope-selective catalytic activity of urease enzyme and exemplifies the link between ¹²CO₂ and urease enzyme.

金属酶脲酶的活性Ni（II）中心在尿素水解之前与底物尿素形成配位体。本研究提供了尿素酶的Ni（II）金属中心与底物尿素之间同位素优先配位的直接实验证据，最终改变了产物的收率。此外，体外实验表明，特定的¹²种CO ₂同位素物种在底物尿素的重同位素[ ¹³ CO（NH ₂）₂]和尿素酶的Ni（II）中心进行更有效的配位，从而最终提高了反应的收率。最后，已经利用人胃中存在的胃病原体幽门螺杆菌的脲酶活性，在体内生理条件下验证了体外观察。因此，本研究为更好地理解脲酶的同位素选择性催化活性铺平了道路，并举例说明了¹² CO ₂和脲酶之间的联系。