First demonstration of an inhibitory activity of milk proteins against human immunodeficiency virus-1 reverse transcriptase and the effect of succinylation

Abstract

A variety of milk proteins including lactoferrin, angiogenin-1, α-lactalbumin, β-lactoglobulin, lactoperoxidase, casein and the novel whey proteins lactogenin and glycolactin were tested for inhibitory activity toward human immunodeficiency virus-1 reverse transcriptase (HIV-1 RT), α-glucosidase, β-glucosidase and β-glucuronidase. Lactoferrin exerted the most potent inhibitory action with an IC 50 of about 6μM. Lactoperoxidase, lactogenin, angiogenin-1 and glycolactin inhibited HIV-1 RT activity with decreasing potencies. β-Lactoglobulin, α-lactalbumin and casein displayed little or no inhibitory effect. Succinylation with succinic anhydride augmented the inhibitory effect of glycolactin, β-lactoglobulin, α-lactalbumin, casein and human lactoferrin. The inhibitory effect of the various milk proteins on the activities of α-glucosidase, β-glucosidase and β-glucuronidase was meager. Succinylation tended to increase the α-glucosidase-inhibitory effect of milk proteins but neither their β-glucosidase-inhibitory nor β-glucuronidase-inhibitory effect was affected.