Variantes não alelicas da região C de uma proteina de Bence Jones (JJO) pertencente ao subgrupo V III

AUTOR(ES)
DATA DE PUBLICAÇÃO

1984

RESUMO

Urine of a patient (J.J.O.) with osteolytic neoplasia characteristic of multiple myeloma was obtained from the School of Medicine. Universidade Estadual de Campinas. Through the qualitative heat test it was detected a Bence Jones proteinuria. Urine JJO was exhaustively dialyzed against deionized water and purified by anion exchange on chromatography. Bence Jones protein JJO was serologically typed as ? and its dimeric configuration shown by SDS polyacrylamide electrophoresis gel The amino acid composition of protein JJO showed: a) 5 moles of half-cystine/mole of protein (which is in agreement with the evidence of dimeric form); b) 1 mole of methionine/ mole of protein; c) total number of residues estimated in 206(not including tryptophane) and d) results similar to the data avaiable for other proteins of this type. Chemical typing was achieved by the isolation of the radioactive C-terminal Pro-Thr-Glu-*CMCys-Ser pentapeptide characteristic of ? type L chains; these data are in agreement with the serological typing. The tryptic Tl octapeptide (Thr-Val-Ala-Pro-Thr-Glu-Cys- Ser) corroborates the chemical typing of JJO as a ? Bence Jones protein. The tryptic T3 peptide (Ser-His-Arg), obtained from peptide mapping, supports the .characterization of JJO as a 190 Arg Oz{-) lambda chain. The iso1ation of the Gln-Ser-Asn-Asn-Lys pentapeptide from peptide mapping allows the partial characterization of JJO as far as position 171 is concerned. The assignement to the Mcg variant was accomplished by the isolation of the peptide Ala-A1a-Pío-S_r-Val-Thr-Leu-Phe- Pro-Pro-Ser-Ser-G1u-Glu-Leu-Glu-Ala-Ser-Lys, which includes two of the three positions involved in the expression of this variant. The detection of Ala 112 and Ser 114 provides evidence of the partial characterization of JJO as an Mcg (-) L chain. The peptide Ala-Gly-Va1-G1u-Thr-Thr-Thr-Pro-Ser-Lys obtained from the neutral region of diagona1 mapping the presence of alanine tn position 157, allowing the showed classi-fication of JJO as a Way(-) variant. The parcial characteri-zation of BJP (JJO) as Mcg(-) was confirmed by the presence of threonine in position 163 in this peptide. One of the half-cystines involved in the C ? intradomain disulphide bridge was detected through the isolation of the tryptic T2 peptide (Ser-Tyr-Ser-Cys-Gln-Val-Thr-His-Glu-Gly-Ser-Thr-Val-Gly-Lys).Based on the information concerning the study of the C domain of the ? protein JJO and the eight types of C ? Domains proposed by FETT &DEUTSCH (l976), one of the following ar-rangements is suggested: Oz(-) Kern(+) Mcg(-) Weir(-) Ev(-) Way(-) Mz(-) or Oz(-) Kern{-) Mcg(-)Weir(-} Ev(-) Way(-) Mz(-)

ASSUNTO(S)

urina - analise imunoglobulinas proteinas

ACESSO AO ARTIGO

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