Antiviral effects of milk proteins: acylation results in polyanionic compounds with potent activity against human immunodeficiency virus types 1 and 2 in vitro.
A number of native and modified milk proteins from bovine or human sources were analyzed for their inhibitory effects on human immunodeficiency virus type 1 (HIV-1) and HIV-2 in vitro in an MT4 cell test system. The proteins investigated were lactoferrin, alpha-lactalbumin, beta-lactoglobulin A, and beta-lactoglobulin B. By acylation of the amino function of the lysine residues in the proteins, using anhydrides of succinic acid or cis-aconitic acid, protein derivatives were obtained that all showed a strong antiviral activity against human immunodeficiency virus type 1 and/or 2. The in vitro IC50 values of the aconitylated proteins were in the concentration range of 0.3 to 3 nM. Succinylation or aconitylation of alpha-lactalbumin and beta-lactoglobulin A/B also produced strong anti-HIV-2 activity with IC50 values on the order 500 to 3000 nM. All compounds showed virtually no cytotoxicity at the concentration used. Peptide-scanning studies indicated that the native lactoferrin as well as the charged modified proteins strongly bind to the V3 loop of the gp120 envelope protein, with Kd values in the same concentration range as the above-mentioned IC50. Therefore, shielding of this domain, resulting in inhibition of virus-cell fusion and entry of the virus into MT4 cells, may be the likely underlying mechanism of antiviral action.
Swart
P J
PJ
Department of Pharmaceutical Pharmacology and Clinical Pharmacy, University Centre for Pharmacy, Groningen, The Netherlands.
Kuipers
M E
ME
Smit
C
C
Pauwels
R
R
deBéthune
M P
MP
de Clercq
E
E
Meijer
D K
DK
Huisman
J G
JG
D000156:Aconitic Acid / Q000494:pharmacology; D000215:Acylation; D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000821:virology; D002417:Cattle; D002478:Cells, Cultured; D015699:HIV Envelope Protein gp120 / Q000187:drug effects / Q000378:metabolism; D015497:HIV-1 / Q000187:drug effects*; D015498:HIV-2 / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D007768:Lactalbumin / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D007781:Lactoferrin / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D007782:Lactoglobulins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D008894:Milk Proteins / Q000737:chemistry / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000187:drug effects / Q000378:metabolism; D000071228:Polyelectrolytes; D011108:Polymers / Q000494:pharmacology*; D011485:Protein Binding; D013386:Succinates / Q000494:pharmacology; D019802:Succinic Acid
D000156:Aconitic Acid; D000998:Antiviral Agents; D015699:HIV Envelope Protein gp120; D007768:Lactalbumin; D007781:Lactoferrin; D007782:Lactoglobulins; D008894:Milk Proteins; D010446:Peptide Fragments; D000071228:Polyelectrolytes; D011108:Polymers; D013386:Succinates; D019802:Succinic Acid; C059762:HIV envelope protein gp120 (305-321)