Improvement of bioactivity of alpha‐lactalbumin through Maillard reaction with dextran

Abstract

α‐Lactalbumin (α‐LA) is an important protein present in the milk of many mammalian species. It is a Ca2+‐binding protein with 4 disulfide bonds. α‐LA and its hydrolysate has been reported to have many physiological functions, such as antimicrobial activity, antiulcer activity and antihypertensive action. However, it was also reported that α‐LA had allergy‐inducing agent. In this study, we tried to synthesize an improved α‐LA through Maillard reaction with polysaccharide dextran (D) which is also well known for its antithrombotic effect. Maillard reaction occurs routinely in cooking and its products are considered safe. α‐LA and D were dry‐heated at 60 °C and 79% relative humidity for 1 week. SDS‐PAGE analysis and absorbance measurements were used to verify the occurrence of the conjugate formation. Antioxidant assays are performed, and immune‐modulating effects are estimated by nitric oxide (NO) production in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). Data showed that α‐LA was successfully conjugated with dextran. D+LA conjugate have shown antioxidant property in a glycation reaction‐time‐dependant manner. Moreover, D+LA significantly inhibited the overproduction of NO compared with the only α‐LA treated sample. Therefore, our study suggest that glycation of α‐LA with dextran (D+LA) might be a useful method for improving some physiological functions of α‐LA.Grant Funding Source: Korea Food Research Institute, Korea