Lipases hydrolyze ester bonds of triacylglycerols and in some conditions, catalyze the synthesis of ester bonds by transesterification. Lipase from Rhizopus niveus exists as a single polypeptide chain with a molecular mass of about 30-34kDa.
Lipase from Rhizopus niveus has been used to determine the positional distribution of fatty acids within triacylglycerol by hydrolysis of the acyl ester linkage at C-1 and C-3. It has also been used to induce intragastric lipolysis and study its effects on felodipine (a medication) release from a hydrophilic, extended release tablet.
Lipase from Rhizopus niveus is specifically used to produce cocoa butter substitutes.
Tri-, di-, and monoglycerides are hydrolyzed (in decreasing order of rate).
1 U corresponds to the amount of enzyme which liberates 1 μmol fatty acid from a triglyceride per minute at pH 7.7 and 40°C (olive oil as substrate)]; 300 U as described above are equivalent to ~1 U using triolein, Cat. No. 62314, at pH 8.0 and 40°C as substrate.
Note: When triacetin is used as substrate, the pH is 7.4. Incubation time: 60 minutes.
Substrate specificity: preferentially hydrolyzes the 1- and 3-positions(middle to long fatty acids); optimum pH 5.0-7.0; optimum temperature 30-45°C; Selective enzymatic removal of protecting functions (C-terminal COOH function)