Effect of the lactoperoxidase system on lipoprotein lipase activity and lipolysis in milk.
The lactoperoxidase/SCN-/H2O2 system (LPS) was found to inhibit lipoprotein lipase (LPL) in milk. Inhibition was related to the amount of SCN-/H2O2 added to milk. Lipolysis was unaltered until LPL activity was decreased to less than 40% of the original activity. When LPL was inhibited further, decreased lipolysis was observed. Purified LPL was also inhibited by LPS, at similar concentrations of SCN-/H2O2 as in milk. It was shown that non enzymically prepared OSCN- inhibited LPL at concentrations comparable to those produced by the LPS. Cysteine could eliminate the effect of LPS on LPL. The sulphydryl reagents dithiobisnitrobenzoic acid and Na tetrathionate had no effect on LPL activity.
D000818:Animals; D002417:Cattle; D003545:Cysteine / Q000494:pharmacology; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D005230:Fatty Acids, Nonesterified / Q000032:analysis; D005260:Female; D007784:Lactoperoxidase / Q000378:metabolism*; D008066:Lipolysis / Q000187:drug effects*; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors*; D008892:Milk / Q000032:analysis / Q000187:drug effects / Q000201:enzymology*; D010544:Peroxidases / Q000378:metabolism*; D013776:Tetrathionic Acid / Q000494:pharmacology; D013861:Thiocyanates / Q000494:pharmacology*
D005230:Fatty Acids, Nonesterified; D013861:Thiocyanates; D013776:Tetrathionic Acid; D004228:Dithionitrobenzoic Acid; D007784:Lactoperoxidase; D010544:Peroxidases; D008071:Lipoprotein Lipase; D003545:Cysteine