94 by high performance liquid chromatography 60 by isolation the activated peptide was analyzed by mass spectrometry aminopeptidase digestion trypsin digestion in combination with mass spectrometry back titration with mercaptoethanol and reaction with 5 5 u2032 dithiobis 2 nitrobenzoic acid and conjugated to alkaline phosphatase for functional testing in an hiv 2 assay the reaction and separation conditions for the preparation of the activated peptide of the invention prepared by processes substantially similar to those as described in the example and the yields of the products so obtained are summarized in the table of trifluoroacetic acid in acetonitrile and 70 by volume of a solution of trifluoroacetic acid in acetonitrile and 85 by volume of a solution of trifluoroacetic acid in acetonitrile and 75 by volume of a solution of trifluoroacetic acid in acetonitrile and 68 by volume of a solution of trifluoroacetic acid in acetonitrile and 65 by volume of a solution of trifluoroacetic acid in acetonitrile and 63 by volume of a solution of trifluoroacetic acid in acetonitrile and 60 by volume of a solution gly cys ser gly lys leu ile cys thr thr ala val pro trp asn ala arg val thr ala ile glu lys tyr leu gln asp gln ala arg leu asn ser trp gly cys ala phe arg gln val cys his thr thr val pro trp asp gln ala arg leu asn ser trp gly cys ala phe arg gln val cys his arg ile leu ala val glu arg tyr leu lys asp gln gln leu leu gly ile trp gly cys ser gly lys leu ile cys thr thr ala val pro trp lys ile leu ala val glu arg tyr leu lys asp gln gln leu leu gly ile trp gly cys ser gly lys.