What factors are related to the enzyme resistance of HEC（Hydroxyethyl cellulose）?
The enzyme resistance of hydroxyethyl cellulose (HEC) is related to the following factors: 1.Molecular structure 2.Degree of substitution 3.PH value 4.Temperature
The enzyme resistance of hydroxyethyl cellulose (HEC) is related to the following factors:
Molecular structure: HEC is a product of cellulose modified by hydroxyethylation, and its hydroxyethyl group is connected to the cellulose skeleton through an ether bond. The enzyme resistance of HEC mainly depends on the uniformity and position of the substituents. Our KDOCEL HEC series (HEC1MS, HEC3MS, HEC6MS, HEC9MS etc) has a more complex cellulose structure(Right side of below picture), and the position of the substituents is different, resulting in different steric hindrances. This structure destroys the crystalline structure of natural cellulose, making it difficult for enzymes to recognize and cut glycosidic bonds, thereby enhancing enzyme resistance.
Degree of substitution: The degree of substitution refers to the average number of hydroxyl groups replaced by hydroxyethyl groups on each glucose unit in the cellulose molecule. Generally speaking, the higher the degree of substitution, the stronger the enzyme resistance of HEC. Because as the degree of substitution increases, the more hydroxyl groups on the cellulose molecule are replaced by hydroxyethyl groups, the fewer enzyme action sites there are, and the more difficult it is to carry out enzymatic hydrolysis. The degree of substitution of general factories is about 1.1-1.8, and a few are better. However, the substitution degree of our KDOCEL HEC series is stable at 2.6-3. The figure below shows the substitution test results of our products and competitors
PH value: Different pH environments will affect the activity of enzymes and the molecular structure of HEC. In a neutral to weakly alkaline environment (pH 6-8), HEC has the best enzyme resistance. This is because in this pH range, the molecular structure of HEC is relatively stable, and the activity of most cellulases is relatively low. Under acidic conditions, HEC molecules may be protonated, resulting in molecular chain contraction, making it easier for the enzyme to approach the action site, and the acidic environment may also accelerate the enzymatic reaction; in a strong alkaline environment, HEC may degrade, thereby affecting its enzyme resistance.
Temperature: Temperature affects both enzyme activity and the stability of HEC. Generally speaking, high temperature activates enzyme activity, but HEC has high thermal stability, and its decomposition temperature is higher than the inactivation temperature of most enzymes. When the temperature exceeds 50℃, the activity of the enzyme will gradually increase, but within a certain temperature range, HEC can still maintain good enzyme resistance. However, if the temperature is too high, HEC may also undergo thermal degradation, resulting in a decrease in its enzyme resistance. For example, in a high temperature environment above 80℃, the molecular chain of HEC may break, making it more vulnerable to enzyme attack. The figure below shows the thermal stability performance of our KDOCEL cellulose ether (HEC3MS, HEC9MS).
