Acid-labile formylation of amino terminal proline of human immunodeficiency virus type 1 p24(gag) was found by proteomics using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry.
HIV-1(LAV-1) particles were collected by ultracentrifugation, treated with subtilisin, and then purified by Sepharose CL-4B column chromatography to remove microvesicles. The lysate of the purified human immunodeficiency virus type 1 (HIV-1) particles was subjected to two-dimensional (2D) gel electrophoresis and stained, and the stained spots were excised and digested with trypsin. The resulting peptide fragments were characterized by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Twenty-five proteins were identified as the proteins inside the virion and the acid-labile formyl group of an amino terminal proline residue of HIV-1(LAV-1) p24(gag) was determined by MALDI-TOF MS before and after weak-acid treatments (0.6 N hydrochloric acid) and confirmed by post-source decay (PSD) of the N-formylated N-terminal tryptic peptide (N-formylated Pro(1)-Arg(18)). The role of formylation has been unclear so far, but it is surmised that the acid-labile formylation of HIV-1(LAV-1) p24(gag) may play a critical role in the formation of the HIV-1 core for conferring HIV-1 infectivity.
Fuchigami
Takashi
T
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-Honmachi, Kumamoto 862-0973, Japan.
Misumi
Shogo
S
Takamune
Nobutoki
N
Takahashi
Ichiro
I
Takama
Michiho
M
Shoji
Shozo
S
D000595:Amino Acid Sequence; D002460:Cell Line; D015180:Electrophoresis, Gel, Two-Dimensional; D005561:Formates / Q000737:chemistry; D016655:HIV Core Protein p24 / Q000737:chemistry* / Q000378:metabolism*; D015497:HIV-1 / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D006851:Hydrochloric Acid / Q000737:chemistry; D008969:Molecular Sequence Data; D011392:Proline / Q000737:chemistry*; D020543:Proteome / Q000032:analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D020860:Subtilisin / Q000494:pharmacology; D014764:Viral Proteins / Q000032:analysis*; D014771:Virion / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure
D005561:Formates; D016655:HIV Core Protein p24; D020543:Proteome; D014764:Viral Proteins; D011392:Proline; D020860:Subtilisin; D006851:Hydrochloric Acid