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GBP28 is a novel human plasma gelatin-binding protein that is encoded by apM1 mRNA, expressed specifically in adipose tissue. Three overlapping clones (two lambda clones and one BAC clone) containing the human plasma gelatin-binding protein (GBP28) gene were isolated and characterized. The GBP28 gene spans 16kb and is composed of three exons from 18bp to 4277bp in size with consensus splice sites. The sizes of the two introns were 0.8 and 12kb, respectively. The gene's regulatory sequences contain putative promoter elements, but no typical TATA box. The third exon of this gene contains a long 3'-untranslated sequence containing three Alu repeats. The exon-intron organization of this gene was very similar to that of obese gene, encoding leptin. We also report the chromosome mapping of this gene by fluorescence in situ hybridization (FISH) using a genomic DNA fragment as a probe. The GBP28 gene was located on human chromosome 3q27. The nucleotide sequence data reported in this paper will appear in the DDBJ/EMBL/GenBank nucleotide sequence databases with the accession numbers ABO12163, ABO12164 or ABO12165.

PHBP is a novel human plasma hyaluronan-binding protein that shows significant homology in amino acid sequence to hepatocyte growth factor activator. Two overlapping clones that encode the human plasma hyaluronan-binding protein (PHBP) gene (HABP2) were isolated and characterized. The PHBP gene spans 35 kb and is composed of 13 exons from 37 to 1,394 bp in size with consensus splice sites. The gene's regulatory sequences contain putative promoter elements, but no typical TATA box. Some exons of this gene showed significant similarities to those of coagulation factor XII, tissue-type plasminogen activator, and urokinase genes in nucleotide length and in intron phasing. We also report the chromosome mapping of this gene by fluorescence in situ hybridization (FISH) using a genomic DNA fragment as a probe. The PHBP gene (HABP2) was located on chromosome 10q25-q26.

The cDNA which encodes the mouse counterpart of human plasma hyaluronan-binding protein (PHBP) was isolated and characterized. The clone contained an insert of 2153 bp, which contained the 1674-bp open reading frame coding for a polypeptide of 558 amino acid residues. The amino acid sequence of mouse PHBP predicted from the nucleotide sequence of cDNA shows reasonable homology to that of human PHBP. Like human PHBP, the amino acid sequence predicted from the nucleotide sequence of mouse PHBP cDNA exhibited significant homology to that of human hepatocyte growth factor activator (HGFA).

A novel hyaluronan-binding protein (PHBP) was purified from human plasma by affinity chromatography on hyaluronan-conjugated Sepharose. The contaminating IgM and albumin in the partially purified preparation were removed with anti-IgG antibody-conjugated Sepharose and anti-albumin antibody-conjugated Sepharose, respectively, and no other contaminant was observed. Finally, 800 micrograms of PHBP was isolated from 500 ml of human plasma. PHBP gave a single 70-kDa band on SDS-PAGE under non-reducing conditions, and 50-kDa and 17-kDa bands under reducing conditions. Thus, PHBP was a heterodimer composed of 50-kDa and 17-kDa subunits, bridged by a disulfide linkage. Both subunits had novel N-terminal amino acid sequences, indicating that PHBP was a novel hyaluronan-binding protein in human plasma. The amino acid sequence deduced from the nucleotide sequence of the cloned PHBP cDNA exhibited significant homology to that of hepatocyte growth factor activator (HGFA). The results of Northern blot analysis indicated that liver, kidney, and pancreas expressed PHBP mRNA. The predicted structure of PHBP showed three epidermal growth factor (EGF) domains, a kringle domain and a serine protease domain, from its N-terminus, although HGFA has a fibronectin type II domain, an EGF domain, a fibronectin type I domain, an EGF domain, a kringle domain, and a serine protease domain, from its N-terminus.

The pig counterpart of human IHRP has been isolated from pig serum, and cDNA clones encoding this counterpart were isolated and characterized. The amino acid sequence of pig IHRP predicted from the nucleotide sequence of its cDNA shows reasonable homology to that of human IHRP. The nucleotide sequence of pig IHRP cDNA is identical to that of the mRNA partially determined to be the heavy chain of pig ITI [Buchman et al. (1990) Surgery 108, 560-566]; it is one of the major mRNAs induced in pig liver on cardiogenic shock. Thus we concluded that the reported mRNA should code for IHRP and not for the heavy chain of ITI. The pig IHRP also seems to be identical to pig-MAP, which was recently reported to be a major acute phase serum protein in pig [Gonzalez-Roman et al. (1995) FEBS Lett. 371, 227-230]. The results suggest that IHRP might be involved in acute phase reactions.

6-O-Sulfation of beta-GlcNAc is an initial step in the biosynthesis of N-linked and O-linked sulfated glycans, which are widely distributed in colonic tissues. However, the biochemical mechanism of this sulfation in human colonic carcinogenesis was still unclear. In this study, we found two types of GlcNAc:-->6sulfotransferases (SulT) in human colonic adenocarcinomas and the adjacent normal mucosa, and we determined their enzymatic characteristics. One SulT, named SulT-a, was present in the adjacent normal mucosa and in non-mucinous adenocarcinomas, whereas the other SulT, named SulT-b, was present only in mucinous adenocarcinomas and adenocarcinomas with a mucinous component. SulT-a preferentially acted on Galbeta1-->3(GlcNAcbeta1-->6)GalNAc(alpha1)-p-nitrophenyl (pNP) and GlcNAcbeta1-->2Man, whereas SulT-b could act not only on these two glycans, but also on GlcNAcbeta1-->3GalNAc(alpha1)-pNP and GlcNAcbeta1-->3Galbeta1-->4Glc. The levels of SulT-a activity were significantly lower in non-mucinous adenocarcinomas than in the adjacent mucosa. In contrast, SulT-b was expressed in mucinous adenocarcinomas and in adenocarcinomas with a mucinous component. These results indicate that there are at least two types of GlcNAc:-->6SulT, SulT-a and -b, in colonic mucosa and adenocarcinomas, and that the occurrence of these enzymes is closely correlated with colonic cancer and the presence of areas of mucin accumulation.