Transcriptional activation of the alpha-1 acid glycoprotein gene by YY1 is mediated by its functional interaction with a negative transcription factor

Regulation of alpha-1 acid glycoprotein (AGP) gene expression involves both positive and negative transcription factors. We have previously identified two dominant factors: positive and negative transcription factors, AGP/EBP and factor B, respectively, involved in the transcription of AGP and other acute-phase response genes. In this report, we present evidence showing that the transcription of the AGP gene is positively regulated by a transcription factor, YY1. The activation of AGP gene by YY1 is mediated by a negative element B in the AGP promoter region. YY1 can also activate the B motif linked to a heterologous promoter. However, YY1 does not bind directly to the B motif per se. Rather, our data suggest that the activation of AGP gene by YY1 may be mediated by its functional interaction with factor B, which recognizes the B motif.

Purification and characterization of nucleolin and its identification as a transcription repressor

Expression of the acute-phase response genes, such as that for alpha-1 acid glycoprotein (AGP), involves both positive and negative transcription factors. A positive transcription factor, AGP/EBP, and a negative transcription factor, factor B, have been identified as the two most important factors responsible for the induction of the AGP gene. In this paper we report the purification, characterization, and identification of a B-motif-binding factor from the mouse hepatoma cell line 129p. The purified factor has been identified as nucleolin by amino acid sequence analysis. Biochemical and functional studies further established that nucleolin is a transcription repressor for regulation of AGP and possibly other acute-phase response genes. Thus, in addition to the many known functions of nucleolin, such as rRNA transcription, processing, ribosome biogenesis, and the shuttling of proteins between the cytoplasmic and nuclear compartments, it may also function as a transcriptional repressor.

Antiarrhythmic effects of BN-063, a newly synthesized adenosine A1 agonist, on myocardial ischaemia in rats

1. It has been shown that adenosine is able to reduce the severity of arrhythmias induced by myocardial ischaemia. In isolated preparations, the antiarrhythmic effect of adenosine on ventricular myocardium is known to antagonize the catecholamine-induced stimulation of intracellular cyclic AMP production, an effect mediated via adenosine A1 receptors. 2. The aim of this study was to evaluate the antiarrhythmic effect of BN-063 (1-cyclopropylisoguanosine), a newly synthesized selective adenosine A1 agonist, on ventricular arrhythmias in rats. 3. Arrhythmias were induced by left coronary artery ligation or by administration of isoprenaline (7 mg kg-1) subcutaneously. Pretreatment with BN-063 (0.25, 0.5 and 1.0 mg kg-1) 10 min prior to occlusion significantly delayed the onset of ventricular arrhythmias, reduced the total number of ventricular premature contraction (VPC) and ventricular tachycardia (VT), decreased the incidence of VT and ventricular fibrillation (VF) and mortality during the first 30 min following left coronary artery ligation. In contrast, pretreatment with 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), an adenosine A1 antagonist, was arrhythmogenic during the ischaemic period. The rate-pressure product, an index for indirect measurement of myocardial oxygen consumption, was also significantly reduced by BN-063 during ligation time. 4. The incidence of VT, VF and mortality was also significantly reduced when BN-063 was administered after left coronary artery ligation. 5. BN-063 converted the VF induced by isoprenaline to normal sinus rhythm and improved the survival rate. 6. It is concluded that, through activation of adenosine A1 receptors, BN-063 can suppress ventricular arrhythmias induced by myocardial ischaemia and catecholamines. The antiarrhythmic actions of BN-063 may be mediated by reducing heart rate and antagonizing the stimulatory effects of catecholamine in myocardial ischaemia.

Bovine conglutinin gene exon structure reveals its evolutionary relationship to surfactant protein-D

Bovine conglutinin (BC), a member of the mammalian C-type collectin subfamily, is a serum protein synthesized in liver that is believed to play a role in natural host defense. Previously, we have characterized a full length BC cDNA and we now describe the partial characterization of a genomic clone that encodes for the BC gene (CGN1). BC is encoded by nine exons spanning > 11 kb and has been localized previously to band 18 of bovine (Bos taurus) chromosome 28. Genomic sequencing demonstrated that the signal peptide/amino-terminal domain, the carbohydrate recognition domain, and the linking peptide, a domain between the collagenous region and the carbohydrate recognition domain, are each encoded by a single exon. The collagenous domain is split into five exons, with the 5' most region being located within the exon that also encodes the signal peptide/amino terminus. The remaining four collagenous domain exons are tandemly arranged with lengths of 117, 108, 108, and 117 bp, respectively. Overall, the BC genomic organization is very similar to that of the human surfactant protein-D gene, SFTP4. On the basis of identical collagen domain structures, we suggest that conglutinin and bovine surfactant protein-D evolved from a gene duplication event occurring in Bovidae after divergence from other mammals.

Bovine conglutinin gene exon structure reveals its evolutionary relationship to surfactant protein-D

Bovine conglutinin (BC), a member of the mammalian C-type collectin subfamily, is a serum protein synthesized in liver that is believed to play a role in natural host defense. Previously, we have characterized a full length BC cDNA and we now describe the partial characterization of a genomic clone that encodes for the BC gene (CGN1). BC is encoded by nine exons spanning > 11 kb and has been localized previously to band 18 of bovine (Bos taurus) chromosome 28. Genomic sequencing demonstrated that the signal peptide/amino-terminal domain, the carbohydrate recognition domain, and the linking peptide, a domain between the collagenous region and the carbohydrate recognition domain, are each encoded by a single exon. The collagenous domain is split into five exons, with the 5' most region being located within the exon that also encodes the signal peptide/amino terminus. The remaining four collagenous domain exons are tandemly arranged with lengths of 117, 108, 108, and 117 bp, respectively. Overall, the BC genomic organization is very similar to that of the human surfactant protein-D gene, SFTP4. On the basis of identical collagen domain structures, we suggest that conglutinin and bovine surfactant protein-D evolved from a gene duplication event occurring in Bovidae after divergence from other mammals.

Poliovirus neutralization by antibodies to internal epitopes of VP4 and VP1 results from reversible exposure of these sequences at physiological temperature

Antisera were raised against peptide sequences that are normally internal in the poliovirus virion. These antisera contain neutralizing activity, but this neutralizing activity is dependent on coincubation of the virus and antisera at 37 degrees C. Immunoprecipitation analyses demonstrate that the neutralization is due to exposure of these normally internal sequences at 37 degrees C and subsequent antibody binding. Exposure of these sequences is reversible. These data demonstrate that the poliovirus particle is a dynamic entity that is capable of undergoing conformational alterations at physiological temperatures. This conformational flexibility provides an explanation for earlier observations of virus neutralization by antibodies to internal epitopes which can be accommodated within the framework of existing models for antibody-mediated neutralization of viral infectivity. Analogies between the sequences which are reversibly exposed at 37 degrees C with those which are irreversibly exposed upon receptor binding suggest that the observed conformational dynamics also may play a role in cell entry.

Bovine conglutinin (BC) mRNA expressed in liver: cloning and characterization of the BC cDNA reveals strong homology to surfactant protein-D

Bovine conglutinin (BC) is a C-type lectin isolated from bovine serum that appears to play a role in first-line host defense. The BC cDNA was cloned from a bovine liver library and the nucleotide (nt) sequence of 1519 bp was determined. The longest open reading frame encoded a 20-amino-acid (aa) signal sequence and a mature protein of 351 aa. Analysis of the nt and deduced aa sequences revealed 87 and 78% identity, respectively, with the sequences of another vertebrate lectin: bovine surfactant protein-D (SP-D). Of interest, the expression of the BC mRNA, as determined by RNase protection assay, is restricted to liver, unlike bovine SP-D, a lung-surfactant protein.

Conglutinin acts as an opsonin for influenza A viruses

Since the 1940's, non-Ig inhibitors of influenza A virus (IAV) hemagglutination activity and infectivity have been recognized in mammalian sera. Recently, the heat labile (beta) inhibitor of this type was identified by indirect methods as the lectin, conglutinin. In support of this hypothesis, we found that purified conglutinin strongly inhibited hemagglutination activity and infectivity of IAV. By using IAV strains with specific variations in glycosylation of the hemagglutinin molecule, we showed these effects to be mediated by binding of conglutinin to high mannose carbohydrate attachments on the viral hemagglutinin. Through the same mechanism conglutinin caused aggregation of IAV particles. Human neutrophils produce hydrogen peroxide upon exposure to IAV. Also, after a brief period of exposure to IAV, neutrophils exhibit depressed responsiveness (deactivation) upon exposure to other stimuli (e.g., chemotactic peptides). These phenomena may be related to the in vivo inflammatory response during IAV infection, and to the propensity of IAV-infected subjects to suffer bacterial superinfection. Pre-incubation of IAV with conglutinin markedly potentiated human neutrophil hydrogen peroxide production in response to the virus. This effect correlated with the ability of conglutinin to aggregate the virus. IAV treated with conglutinin also caused significantly less neutrophil deactivation than did the unopsonized virus. These enhancements of neutrophil respiratory burst responses by conglutinin were again mediated by binding of the lectin to viral carbohydrates. The mammalian C-type lectin family includes conglutinin, mannose-binding protein, and surfactant proteins A and D. These lectins may be important constituents of the initial host response to IAV, by inhibiting IAV infectivity directly, causing viral aggregation, and acting as opsonins to enhance phagocyte responses to the virus.

Conglutinin acts as an opsonin for influenza A viruses

Since the 1940's, non-Ig inhibitors of influenza A virus (IAV) hemagglutination activity and infectivity have been recognized in mammalian sera. Recently, the heat labile (beta) inhibitor of this type was identified by indirect methods as the lectin, conglutinin. In support of this hypothesis, we found that purified conglutinin strongly inhibited hemagglutination activity and infectivity of IAV. By using IAV strains with specific variations in glycosylation of the hemagglutinin molecule, we showed these effects to be mediated by binding of conglutinin to high mannose carbohydrate attachments on the viral hemagglutinin. Through the same mechanism conglutinin caused aggregation of IAV particles. Human neutrophils produce hydrogen peroxide upon exposure to IAV. Also, after a brief period of exposure to IAV, neutrophils exhibit depressed responsiveness (deactivation) upon exposure to other stimuli (e.g., chemotactic peptides). These phenomena may be related to the in vivo inflammatory response during IAV infection, and to the propensity of IAV-infected subjects to suffer bacterial superinfection. Pre-incubation of IAV with conglutinin markedly potentiated human neutrophil hydrogen peroxide production in response to the virus. This effect correlated with the ability of conglutinin to aggregate the virus. IAV treated with conglutinin also caused significantly less neutrophil deactivation than did the unopsonized virus. These enhancements of neutrophil respiratory burst responses by conglutinin were again mediated by binding of the lectin to viral carbohydrates. The mammalian C-type lectin family includes conglutinin, mannose-binding protein, and surfactant proteins A and D. These lectins may be important constituents of the initial host response to IAV, by inhibiting IAV infectivity directly, causing viral aggregation, and acting as opsonins to enhance phagocyte responses to the virus.

An immune complex selective affinity column utilizing site-specific attachment of bovine conglutinin

A simple method to isolate immune complexes by column chromatography is described. The immune complex affinity column was constructed by the site-specific attachment of bovine conglutinin to agarose. Covalent attachment of conglutinin to agarose was achieved via hydrazone chemistry, which reacts aldehydes of oxidized oligosaccharides in the collagenous domain of conglutinin with hydrazide functional groups in the solid support. The constructed conglutinin affinity column captured complement-fixed model immune complexes of heat-aggregated human IgG and more classical complexes of chicken ovalbumin-anti-chicken ovalbumin. Neither the nonfixed immune complexes nor their individual components were retained by the column. The captured material was specifically eluted with EDTA without the use of low pH. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blot analysis, and protein sequence analysis of the eluates revealed the presence of the expected individual components, verifying that both antibody and antigen used to prepare the soluble immune complexes were recovered from the conglutinin column. The advantages of this approach over traditional methods of immune complex isolation and characterization are discussed.

The effect of ostial opening on experimental maxillary sinusitis in rabbits

Obstruction of the natural ostium is known to be one of the major factors in the pathogenesis of maxillary sinusitis. To explore the therapeutic effect of ostial patency, sinusitis was induced in 32 rabbits by obstruction of the natural ostium and inocculation of Streptococcus pneumoniae. They were divided into two groups: the first ("open") group included 16 rabbits with experimentally induced sinusitis, from which bone chips for obstruction of the natural ostium were removed after a period of 5 days, and the second ("closed") group included 16 rabbits with continuous obstruction of the natural ostium. The induction of sinusitis was found to be successful in all cases, when examined after five days. The amount of nasal and sinus secretion as well as histopathological findings of the sinus mucosa were investigated with light microscopy, scanning and transmission electron microscopy, two and four weeks after induction of sinusitis. The findings were significantly improved in the "open" group.

In vitro DNA methylation inhibits FMR-1 promoter

In fragile X syndrome, the FMR-1 gene is changed by a CGG repeat mutation and an abnormal methylation at a CpG-island 5' to the gene. To elicit if methylation itself inactivates the gene, FMR-1 promoter was defined by deletion mapping and primer extension assay and was analyzed by in vitro methylation. Promoter activity was measured by transient expression and chloramphenicol acetyl transferase assay. Although this promoter contains several HpaII sites, it was not affected by methylation with HpaII methylase. However, the promoter was completely repressed by methylation with M. SssI which methylates all cytosines of CpG dinucleotides. This repression could not be overridden by SV-40 enhancer. This study indicates that methylation could be the direct cause of FMR-1 inactivation in fragile X syndrome.

The human brain cholecystokinin-B/gastrin receptor. Cloning and characterization

The predominant brain cholecystokinin receptor (CCK-B/gastrin) has been implicated in mediating many of the central effects of cholecystokinin, including anxiety, panic attacks, satiety, and analgesia, suggesting it is an important pharmacologic target. We now report the cloning and characterization of the cDNA encoding the human brain CCK-B/gastrin receptor. The cDNA was isolated from a human brain library by low stringency screening using the canine "gastrin" receptor cDNA as a hybridization probe. Nucleotide sequence analysis revealed an open reading frame encoding a 447-amino-acid protein with seven putative hydrophobic transmembrane domains and significant homology with other known members of the gastrin/cholecystokinin receptor family. Agonist and antagonist affinities of the recombinant human brain receptor expressed in COS-7 cells are consistent with a classical "CCK-B" receptor as defined by the literature. In COS-7 cells expressing the cloned receptor, CCK-8-stimulated phosphatidylinositol hydrolysis and intracellular Ca2+ mobilization suggesting second messenger signaling through phospholipase C. CCK-B/gastrin receptor transcripts were identified in human brain, stomach, and pancreas using high stringency Northern blot analysis. Southern blot hybridization analysis of human genomic DNA indicates that a single gene encodes both the brain and the stomach CCK-B/gastrin receptors. Our data suggest that the CCK-B and gastrin receptors are identical and that the long standing distinction between them may no longer apply.

A single amino acid of the cholecystokinin-B/gastrin receptor determines specificity for non-peptide antagonists

The brain cholecystokinin-B/gastrin receptor (CCK-B/gastrin) has been implicated in mediating anxiety, panic attacks, satiety, and the perception of pain. The canine and human CCK-B/gastrin receptors share 90% amino-acid identity and have similar agonist affinities. These receptors can be selectively blocked by the non-peptide benzodiazepine-based antagonists L365260 (ref. 8) and L364718 (ref. 9); however, the binding of these antagonists to the human and canine receptors differs by up to 20-fold, resulting in a reversal of affinity rank order. Here we report the identification of a single amino acid in the sixth transmembrane domain of the CCK-B/gastrin receptor that corresponds to valine 319 in the human homologue and which is critical in determining the binding affinity for these non-peptide antagonists. We show that it is the variability in the aliphatic side chain of the amino acid in position 319 that confers antagonist specificity. Substitution of valine 319 with a leucine residue decreases the affinity for L365260 20-fold while concomitantly increasing the affinity for L364718. An isoleucine in the same position of the human receptor selectively increases affinity for L364718. Interspecies differences in the aliphatic amino acid occupying this single position selectively affect antagonist affinities without altering the agonist binding profile. We therefore conclude that the residues underlying non-peptide antagonist affinity must differ from those that confer agonist specificity. To our knowledge, these findings are the first example in which a critical antagonist binding determinant for a seven-transmembrane-domain peptide hormone receptor has been identified.

Prognostic significance of human papillomavirus detected with polymerase chain reaction in cervical cancer

In order to investigate the prognostic factors of cervical cancer and its association with human papillomavirus (HPV), we analyzed 50 specimens of cervical cancer with a DNA polymerase chain reaction (PCR) mainly to detect HPV types 16 (HPV 16) and 18 (HPV 18). The result showed that at least 74% (37/50) of the specimens had HPV DNA. Among them, 54% (20/37) of the cases were HPV 16 and 32% (12/37) were HPV 18. These HPV DNA positive patients had poorer differentiation in histology than the HPV DNA negative patients. We draw no conclusion about the prognostic significance of HPV DNA in cervical cancer. Perhaps more cases should be analyzed.

Induction of liver alpha-1 acid glycoprotein gene expression involves both positive and negative transcription factors

Expression of the alpha-1 acid glycoprotein (AGP) gene is liver specific and acute phase responsive. Within the 180-bp region of the AGP promoter, at least five cis elements have been found to interact with trans-acting factors. Four of these elements (A, C, D, and E) interacted with AGP/EBP, a liver-enriched transcription factor, as shown by footprinting analysis and by an anti-AGP/EBP antibody-induced supershift in a gel retardation assay. Modification of these sites by site-directed mutagenesis coupled with transfection analysis indicated that AGP/EBP binding to all of these sites resulted in positive regulation of the promoter. Dose-response data suggest that AGP/EBP binding to these sites results in the cooperative activation of the promoter. In contrast, functional assays showed that element B is a negative regulatory element; this element is recognized by heat-stable DNA-binding factors which are found in many cells and tissues. The regulation of these binding proteins was studied in rat liver treated with lipopolysaccharide (LPS), which induced an acute-phase reaction. We found that LPS treatment resulted in a two- to threefold increase in AGP/EBP activity and a severalfold decrease in the activity of factors that bind to element B in the liver. These results indicate that expression of the AGP gene can be regulated by both positive and negative factors and that the modulation of these factors can account for the LPS induction of the AGP gene.

Nonrandom integration of retroviral DNA in vitro: effect of CpG methylation

We have developed a PCR-based system that allows us to assess the relative frequency of use of specific bases as targets for the avian leukosis virus in vitro integration system. Using this system, we tested the effect of 5-methylation of cytosine in runs of CpG on the distribution of integration target sites. We found that the distribution of preferred integration sites was not uniform along the target DNA; rather, there was a distinct and reproducible pattern of frequently used sites. This pattern was independent of orientation of the integrated DNA, and of overall structure and sequence of the target and fragment amplified. Methylation did not inhibit integration into CpG dinucleotides; on the contrary, this modification created highly preferred targets within runs of alternating CpG. Finally, similar but not identical specificity was observed by using preintegration complexes in infected extracts or purified integrase and DNA as enzyme and substrate. Thus, most of the specificity observed is conferred by interaction of integrase and targets, although it may be modified by other viral and/or cellular components.

Expression cloning and characterization of the canine parietal cell gastrin receptor

Gastrin is an important stimulant of acid secretion by gastric parietal cells and is structurally related to the peptide hormone cholecystokinin (CCK). The pharmacologic properties of the parietal cell gastrin receptor are very similar to the predominant CCK receptor in the brain, CCK-B. Neither the gastrin nor the CCK-B receptor have been cloned thus far, making it difficult to resolve whether these two receptors are distinct. We have isolated a clone encoding the canine gastrin receptor by screening a parietal cell cDNA expression library using a radioligand-binding strategy. Nucleotide sequence analysis revealed an open reading frame encoding a 453-amino acid protein with seven putative hydrophobic transmembrane domains and significant homology with members of the beta-adrenergic family of G protein-coupled receptors. The expressed recombinant receptor shows the same binding specificity for gastrin/CCK agonists and antagonists as the canine parietal cell receptor. Gastrin-stimulated phosphatidylinositol hydrolysis and intracellular Ca2+ mobilization in COS-7 cells expressing the cloned receptor suggest second-messenger signaling through phospholipase C. Affinity labeling of the expressed receptor in COS-7 cells revealed a protein identical in size to the native parietal cell receptor. Gastrin receptor transcripts were identified by high-stringency RNA blot analysis in both parietal cells and cerebral cortex, suggesting that the gastrin and CCK-B receptors are either highly homologous or identical.

Myristate modification does not function as a membrane association signal during poliovirus capsid assembly

The myristate moiety is required for poliovirus assembly. Unlike most other myristoyl-modified proteins, which are membrane associated, no specific membrane association of the poliovirus capsid proteins or assembly intermediates was observed. Furthermore, no apparent differences in membrane association of wild-type and myristoylation deficient mutant viruses could be detected in this analysis. Thus, during poliovirus assembly, the myristate modification is not required as a membrane targeting signal but is more likely involved in structural interactions between protomer subunits.

[Detection of open processus vaginalis by radionuclide scintigraphy]

The processus vaginalis usually obliterates spontaneously from the inguinal ring to the scrotum after the descent of testis has been completed. Under certain conditions, it can be reopened. In present reports, 3 cases with open processus vaginalis were described. The first one is a case of uremia due to chronic glomerulonephritis, suddenly suffering from right scrotal and penile swelling, following continuous ambulatory peritoneal dialysis (CAPD) for 4 months. The second one is a case of uremia, due to unknown etiology, suddenly developing right scrotal and penile swelling after 5 months of CAPD. The third one is a case with uremia of uncertain etiology, suffering from bilateral scrotal and penile swelling in the first month of CAPD, following a wrong procedure, by adding some 200cc more dialysate. Three mCi of Tc-99m phytate or pertechnetate, added into the bag of peritoneal dialysate for each patient, allowed us to visualize a peritoneo-vaginal communication. After surgery one of the patients who had been given followup treatment by radionuclide scintigraphy showed no passage of the labeled infusion in the swollen side of the scrotum. A previous postmortem study of adults dying without clinically apparent inguinal hernia demonstrated an open processus vaginalis in 20% of groins examined. Thus, this study suggests that in placement of catheters for CAPD or ventriculo-peritoneal shunt, Tc-99m pertechnetate/phytate may be given through intraperitoneal injection to detect a subclinical open processus vaginalis.

[Proptosis and optic nerve compression caused by unilateral ethmoidal pyocele: a case report]

This paper presents the case of a 29 year-old male with a left ethmoidal pyocele with orbital and intracranial extensions causing proptosis and a temporal visual field defect of the left eye. The patient had a history of nasal injury as a result of traffic accident eleven years ago, and was well until four months prior to his first visit at which time he had an onset of left eye pain, proptosis, and blurring of vision developed following a URI episode. Since then, fluctuation of symptoms was noted with exacerbation when contracting a common cold. The left ethmoidal pyocele was diagnosed via clinical features and roentgenographic findings. The patient received a Caldwell Luc Operation with endonasal ethmoidectomy and the postoperative condition was good except for constriction of the entire visual field and the depression of temporal internal isopters of the left eye.

Relationship of avian retrovirus DNA synthesis to integration in vitro

An in vitro integration system derived from avian leukosis virus-infected cells supports both intra- and intermolecular integration of the viral DNA. In the absence of polyethylene glycol, intramolecular integration of viral DNA molecules into themselves (autointegration) was preferred. In the presence of polyethylene glycol, integration into an exogenously supplied DNA target was greatly promoted. Analysis of integration intermediates revealed that the strand transfer mechanisms of both reactions were identical to those of retroviruses and some transposons: each 3' end of the donor molecule is joined to a 5' end of the cleaved target DNA. The immediate integration precursor appears to be linear viral DNA with the 3' ends shortened by 2 nucleotides. Finally, in the avian system, most cytoplasmic viral DNA appears to be incomplete and further DNA synthesis is required for integration in vitro.

Primary structure of bovine conglutinin, a member of the C-type animal lectin family

We report the complete amino acid sequence of bovine conglutinin obtained by structural characterization of peptides derived from the protein by various chemical and enzymatic fragmentation methods. The protein consists of 351 amino acid residues including 55 apparent Gly-X-Y repeats with two interruptions. This 171-residue-long collagenous domain separates a short noncollagenous NH2-terminal region of 25 residues from the 155-residue-long globular COOH terminus revealing the structural relation of conglutinin with mannose-binding proteins, pulmonary surfactant-associated proteins, and a complement component C1q. Eight hydroxylysine residues were found in the collagenous domain. All of these hydroxylysine residues which occupy a Y position in a Gly-X-Y triplet are possible glycosylation sites since no phenylthiohydantoin amino acid was identified in automated Edman degradation cycles corresponding to these sites. The noncollagenous COOH domain of conglutinin, on the other hand, contains a carbohydrate recognition domain which shares substantial sequence homology with C-type animal lectins. Conglutinin has the greatest sequence similarity with mannose-binding proteins and pulmonary surfactant-associated proteins.