Guinea pig alpha(1)-microglobulin/bikunin: cDNA sequencing, tissue expression and expression during acute phase

cDNA encoding alpha(1)-microglobulin/bikunin (AMBP) was amplified from guin ea pig (Cavin porcellus) liver mRNA by reverse transcription-polymerase cha in reaction (RT-PCR) and rapid amplification of cDNA ends methods, cloned a nd sequenced. The deduced amino acid sequence was found to be homologous to the sequence of AMBP of other mammals (69-76% amino acid identity). It has two Kunitz-type trypsin inhibitor domains in the bikunin part as reactive sites, one in the N-terminal region and another in the C-terminal region. T he N-terminal inhibitor domain sequence is well-conserved, but the P1 resid ue of the C-terminal inhibitor domain sequence was found to be Gin rather t han Arg, a residue highly conserved in the AMBP of seven other mammals exam ined to date. By RT-PCR and nested PCR, AMBP mRNA was detected not only in liver tissue, previously known to be a site of its synthesis, but also in p ancreas, stomach, small intestine, colon, lung, spleen, kidney, testis, ske letal muscle, and leukocytes, but not in brain or heart. We examined the AM BP mRNA levels in guinea pig liver by RT-PCR, comparing normal levels and t hose in a state of inflammation. The mRNA levels, however, did not signific antly change. (C) 1999 Elsevier Science Inc. All rights reserved.