Proteins and reducing sugars can be conjugated by glycation reaction which is Maillard reaction. We have tried to find a new functional material through this reaction. In the previous study, we found that there was a potency of immune‐modulating effect on alpha‐lactalbumin (LA) and dextran (D) conjugate (LADC). There was no a significant difference between LA and LADC in terms of immune response in RAW 264.7 macrophage cell line. However, in this study, the immune‐enhancing effects of high molecular weight portion of LADC were shown DLA in RAW 264.7 was shown. LA and D were dry‐heated at 60¡É and 79% relative humidity for 1 and 15 days. SDS‐PAGE analysis was used to confirm the occurrence of the conjugated formation. 100 kDa membrane cut‐off was carried out to gain a high molecular weight portion of LADC. Immune‐enhancing effects were screened by nitric oxide (NO) production. TNF‐α, IL‐1β and IL‐6 cytokines were estimated in vitro. Data showed that the high molecular weight cutoff portion of LADC (LADCCO) showed dramatically increase of NO production. Also, LADCCO treated group presented high expression of immune‐related cytokines, TNF‐α, IL‐1β, and IL‐6, in RAW 264.7 macrophages. Therefore, our study suggests that high molecular weight cutoff portion of dextran glycated with alpha‐lactalbumin might be a new useful material for enhancing the immune responses.

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