Detection of the active components of calf thymus nuclear proteins (TNP), histones that are binding with high affinity to HIV-1 envelope proteins and CD4 molecules.
VGV-1, a clinical-grade formulation of bovine thymus nuclear protein (TNP) has been demonstrated to possess anti-viral activity in HIV-1 patients in five clinical trials, one of which was placebo controlled double-blinded. However, to date molecular mechanisms remain to be identified. Using surface plasmon resonance we observed TNP components bind with high affinity to HIV-1 proteins involved in viral entry, gp41 and pg120, as well as the T cell HIV-1 receptor CD4. To identify protein components of TNP, gel electrophoresis was performed followed by tandem mass spectrometry (MS/MS). Searching of bovine protein databases revealed the presence of numerous histones. Further analysis of TNP by immunoaffinity chromatography using gp120 and CD4 molecules as targets followed by gel electrophoresis and MS/MS analysis confirmed these data, demonstrating that H1.1, H2B, H4, and H2A histones are the active component of TNP that bind to HIV envelop glycoprotein and its receptor. To conclusively demonstrate binding of histones to target proteins, we repeated the surface plasmon resonance experiments using commercially available bovine histones and demonstrated high-affinity interaction of histones with gp120, and CD4. The binding of histone proteins to CD4, as well as viral molecules has profound implications for basic understanding of immune functions as well as a possible mechanism of VGV-1 activity in AIDS patients.
Mamikonyan
Grigor
G
The Institute for Molecular Medicine, the Department of Molecular Immunology, Huntington Beach, CA 92647, USA.
Kiyatkin
Anatoly
A
Movsesyan
Nina
N
Mkrtichyan
Mikayel
M
Ghochikyan
Anahit
A
Petrushina
Irina
I
Hwang
Jimmy
J
Ichim
Thomas E
TE
Keledjian
Haig
H
Agadjanyan
Michael G
MG
D000818:Animals; D015704:CD4 Antigens / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D002417:Cattle; D015699:HIV Envelope Protein gp120 / Q000378:metabolism*; D015700:HIV Envelope Protein gp41 / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D020349:Surface Plasmon Resonance; D013950:Thymus Gland / Q000737:chemistry
D015704:CD4 Antigens; D002352:Carrier Proteins; D015699:HIV Envelope Protein gp120; D015700:HIV Envelope Protein gp41; D006657:Histones; D009687:Nuclear Proteins; C500647:VGV-1 protein, calf