By means at' rcvcrsc~phns~~ t1Pt.C 1 ditkrcnl praklnx were ublnina8 frtlm upptircnlly puritkd pig curinaphtl major krzic protein CMBBI nad ~hcae prakins were named OMPBI nnd OMBP~.~I wax rewnlcd thrl\ these 2 crrmpuncnrr rrTMBP huvcximilAr molcculr~r wci&rtsr\nd pl vtituc$, although the amino acid comporikann wera nlightly ditkcnl, In the prcvtuur study, WC cluned und rcqucnecd CIMPBI eRNA. Hrrc we obt&cd another clone by plaque hybrtdixrtion using 21 rcrnning probe synthrrirrd by RWRX ar pcllymcrurr chain rctrckm, Ahcr ncqucncing. it kcnmc appnrcnr that this clanccorrcspondcd 16 CIMBR?.
INTRODUCTION
It is generally believedthat the allergic diseases associated with cosinophilia are those in which immediate.type hypersensitivity reaction is predominant and that in all species the eosinophil is characterized by the presence of large intracytoplasmic granules, Ultrastructural studies indicate that these granules are bounded by a double-layered membrane and contain a rectangular crystalline-like core surrounded by a less electron-dense matrix [l]. Although the granule contains a number of biologically active agents, approximately half the granule consists of the arginine-rich major basic protein (MBP) [2], In asthma, MBP is deposited in and around the bronchi [2]. In relation to this, it has been shown that MBP is not only capable of [5,6). In experimental animals, guinea pig MBP was purified by Gleich et al. [7], We have reported that guinea pig MBP was composed of 2 different proteins, named CMBPl and GMBPZ, which are similar in molecular weights and pI values [$I. After cDNA cloning of GMBPl, it was found tha.t cDNA of GMBPl encoded preproGMBP1 with 3 domains: signal peptide, acidic domain, and mature GMBPl [$I, In the present study, cDNA cloning of GMBPZ was carried out. Comparing human MBP with 2 guinea pig MBPs, it was indicated that bhese 3 MBPs are similar not only in physical property but also in chemical structure.
MATERIALS AND METHODS
b Purificalion of guinea pig eosinophil MBPThe procedures employed to collect the purified guinea pig MBP are the same as those reported previously [a]. Briefly, male Hartley guinea pigs (300-350 g) were intraperitoneally injected once a week with 1 mg/animal of polymixin B (Sigma) and t mg/animal of ascaris suum extract. Six weeks later, the peritoneal exudated cells were col. lected by perfusing the abdominal cavity of anesthetized animals with 50 ml of physiological buffered solution (PBS, in mM: NaCl, 154: KCI, 2.7; CaCl2,0.9; HEPES, 5 (pH 7.4)), By means of Percoll densi.Published by Elsevier Science Publishers B. V.