HERPES-SIMPLEX VIRUS PROTEINS ARE DAMAGED FOLLOWING PHOTODYNAMIC INACTIVATION WITH PHTHALOCYANINES

The photodynamic inactivation of herpes simplex virus type 1 (HSV-1) b y two phthalocyanines (Pcs), the cationic dye HOSi-PcOSi(CH3)(2)(CH2)( 3)N+ (CH3)(3)I- (Pc5) and the amphiphilic dye aluminum dibenzodisulfop hthalocyanine hydroxide (AlN2SB2POH), has been compared with that by t he anionic dye, Merocyanine 540 (Mc540). Both Pc derivatives demonstra te a remarkable virucidal activity upon Light activation even 3 h afte r the onset of HSV-1 adsorption, while Mc540 is effective far only 30 min after adsorption. Since fusion and virus penetration are promoted by membrane glycoproteins, we have studied the damage to viral protein s following photodynamic treatment (PDT) of HSV-1 and its relation to inactivation. The effect of AlN2SB2POH PDT is assessed by sodium dodec yl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Major change s are found in the protein profile of PDT-treated HSV-1. A reduced abi lity of specific antibodies to react with HSV-1 major envelope protein s is detected by employing the Western blot assay. In particular, we d emonstrate the related changes of glycoprotein D (gD), a structural pr otein of the HSV envelope. Since the envelope proteins participate in viral entry into the host cell, these alterations to viral envelope pr oteins may impair their ability to participate in early events of vira l entry, leading to reduced infectivity of HSV-I. In contrast, no sign ificant changes in the proteins' electrophoretic mobility could be see n after PDT with Mc540 or with Pc5. When HSV-1 purified proteins are s ubjected to combined electrophoretic and electro-osmotic forces on cel lulose acetate, there is a shift in their cathode mobility, which may indicate changes in the protein mass and protein net charges following AlN2SB2POH photosensitization. There are only minor changes in the vi rus proteins, assayed as above, when HSV-1 is treated with Pc5. (C) 19 98 Elsevier Science S.A. All rights reserved.