Published Amino Acid Sequence Research Articles

Comparison of Hydration Behavior of Bovine and Caprine Caseins As Determined by Oxygen-17 Nuclear Magnetic Resonance: Effects of Salt

Oxygen-17 nuclear magnetic resonance (NMR) transverse relaxation measurements at 4.7 T were used to study the hydration properties of bovine and caprine casein solutions with and without NaCl. Measurements were carried out at 21 degrees C and pD 6.95. Nonlinear protein concentration dependences were observed for the oxygen-17 NMR transverse relaxation rates, but the fitting of the data did not require any higher order virial coefficients; only B0 was needed. This indicates that long-range, charge-charge repulsive dominate entirely the protein activity in solution. Estimates of the bovine casein average net charge were obtained from the virial coefficient (B0) and the partial specific volume; these are in accord with published amino acid sequence data. For bovine casein, the alphas1- and beta-components occur in nearly equal amounts, whereas in caprine casein, beta-casein is the predominant species and beta-casein varies from high to low values, suggesting altered protein-protein interactions. Hydration levels of caprine casein high in the alphas1-casein component when compared with those of bovine casein (intermediate hydration) and the low alphas1-caprine casein (low hydration) are interpreted in terms of trapped and preferential interactions with water on the basis of quantitative differences in casein monomer contents.

A Double Mutant of Sperm Whale Myoglobin Mimics the Structure and Function of Elephant Myoglobin

The functional, spectral, and structural properties of elephant myoglobin and the L29F/H64Q mutant of sperm whale myoglobin have been compared in detail by conventional kinetic techniques, infrared and resonance Raman spectroscopy, 1H NMR, and x-ray crystallography. There is a striking correspondence between the properties of the naturally occurring elephant protein and those of the sperm whale double mutant, both of which are quite distinct from those of native sperm whale myoglobin and the single H64Q mutant. These results and the recent crystal structure determination by Bisig et al. (Bisig, D. A., Di Iorio, E. E., Diederichs, K., Winterhalter, K. H., and Piontek, K. (1995) J. Biol. Chem. 270, 20754-20762) confirm that a Phe residue is present at position 29 (B10) in elephant myoglobin, and not a Leu residue as is reported in the published amino acid sequence. The single Gln64(E7) substitution lowers oxygen affinity approximately 5-fold and increases the rate of autooxidation 3-fold. These unfavorable effects are reversed by the Phe29(B10) replacement in both elephant myoglobin and the sperm whale double mutant. The latter, genetically engineered protein was originally constructed to be a blood substitute prototype with moderately low O2 affinity, large rate constants, and increased resistance to autooxidation. Thus, the same distal pocket combination that we designed rationally on the basis of proposed mechanisms for ligand binding and autooxidation is also found in nature.

Partial Complementary Deoxyribonucleic Acid Cloning of Equine Relaxin Messenger Ribonucleic Acid, and its Localization within the Equine Placenta1

To determine the site of relaxin gene expression in equine placentae, a set of degenerate oligonucleotide primers was made according to the published amino acid sequence of the A- and B-chain of equine relaxin (eRXN). Total cellular RNA (tcRNA) from equine placentae at about 120 and 300 days of pregnancy was subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) with use of these primers. A single amplification product of approximately 430 bp was detected in each case by agarose gel electrophoresis. The PCR product was ligated into Bluescript plasmid and sequenced to confirm the identity of the clone as an eRXN cDNA fragment. Nucleic acid sequence analysis revealed a 428-bp eRXN cDNA fragment encoding for parts of the A- and B-chain and the connecting peptide (109 residues). Northern analysis of tcRNA from placentae of 120 and 300 days of pregnancy was carried out with use of antisense digoxigenin-labeled cRNA generated from the cDNA clone, and a single transcript of approximately 1 kb was detected. In situ hybridization on placental tissue at 120 and uteroplacental tissue at 300 days of pregnancy indicated that only the fetal trophoblastic cells expressed eRXN mRNA transcripts. The identity of these cells was confirmed by their positive staining with an antibody specific for equine trophoblast (cell surface) protein. Relaxin peptide was also detected immunohistochemically in samples of the same placental tissues. This is the first report of the nucleic acid sequence of eRXN. The study identified fetal trophoblast cells as the site of eRXN mRNA expression and protein secretion in the equine placenta.

Molecular Cloning of a cDNA Encoding Putative Molt-Inhibiting Hormone from the Blue Crab, Callinectes sapidus

A cDNA library was constructed using poly(A+) RNA isolated from eyestalk neural ganglia of the blue crab, Callinectes sapidus. The library was screened using a probe generated by PCR based on the published amino acid sequence of molt-inhibiting hormone from the shore crab, Carcinus maenas. DNA sequence analysis of one positive clone revealed a 339 bp open reading frame encoding a 78-residue putative molt-inhibiting hormone and a 35-residue signal peptide. The deduced amino acid sequence of C. sapidus molt-inhibiting hormone is 79% homologous with that of C. maenas. Northern blot analysis, using a fragment of the cloned molt-inhibiting hormone cDNA as probe, revealed specific hybridization to a single band (∼1.4 kb) in RNA extracted from eyestalk but not control tissues.

Peptide Mapping of Bovine T‐Cell Epitopes for the 38 kDa Tuberculosis Antigen

Mycobacterium bovis infection in cattle continues to be a problem in several regions, partly due to inadequate diagnostic tests. The aim of this study was to use an experimental model of the natural disease to identify T-cell epitopes from the mycobacterial 38 kDa antigen as potentially specific diagnostic reagents. A panel of overlapping synthetic peptides (16-mers with a five-residue overlap) were produced from the published amino acid sequence. It was found that peripheral blood lymphocytes from at least three of four experimentally infected animals, which were considered to be in either Th1- or Th1/Th2-dominated stages of anti-mycobacterial immunity, proliferated in response to five epitopes (residues 1-27, 88-107, 122-138, 243-260 and 307-328). However, in vitro production of IFN-gamma was detected only in response to epitope 122-138, indicating a role in protective immunity. The peptides were not recognized by control, uninfected animals, but all epitopes showed various degrees of recognition by animals which were field reactors to intradermal tuberculin testing. Furthermore, epitopes 1-27, 88-107 and 122-138 were recognized by four breeds of cattle and by animals from separate herds, suggesting genetic permissiveness in recognition which would be essential in the development of a diagnostic test.

Electrospray ionisation mass spectrometry of lens crystallins: Verification and detection of errors in protein sequences of bovine γ-crystallins

Individual bovine gamma crystallins have been isolated by gel permeation chromatography (GPC) followed by fast protein ion-exchange liquid chromatography (FPLC). Electrospray ionisation (ESI) mass spectrometric examination of the isolated proteins confirms the relative molecular masses (RMM) of three γ-crystallins, i.e. γS, γII (or γB) and γIIIb. The RMM of γIVa and γIIIa, however, are inconsistent with the reported sequences of these proteins. Reduction and carboxymethylation followed by ESI mass spectrometric analysis is shown to be a rapid and convenient method for determining the sulphydryl content of these proteins. In the case of γIIIa and γIVa, this showed these proteins each contain five cysteine residues, compared with ten and six, respectively, in the published sequences. The number of cysteine residues is significant since intramolecular disulphide bonds may have a marked effect on the tertiary structures of these proteins. In addition, the RMM of a protein that we have tentatively assigned as γIVb, which has not been sequenced, is reported here. This study demonstrates the considerable advantages offered by ESI mass spectrometry for confirming published amino acid sequences and detecting sequence errors.

On the site by which α-dendrotoxin binds to voltage-dependent potassium channels: Site-directed mutagenesis reveals that the lysine triplet 28–30 is not essential for binding

We constructed a synthetic gene encoding the published amino acid sequence of DTx from Dendroaspis angusticeps, a ligand of voltage-dependent postassium channels that facilitates neurotransmitter release. We expressed it in Escherichia coli as a fusion protein secreted in the culture medium. The recombinant DTx was generated in vitro by chemical treatment and recovered as two isoforms. One of them (rDTx), like the venom toxin, has an N-terminal pyroglutamate whereas the other (rQDTx) has a free N-terminal glutamine. Chromatographic differences between rDTx and natural DTx led us to re-examine the amino acid sequence of natural DTx. In contrast to what was previously published, position 12 was an Asp and not Asn. Despite this difference, rDTx and DTx had similar toxicity in mice and binding affinity to synaptosomes, suggesting that residue 12 is not important for DTx function. Nor is the N-terminal residue implicated in DTx function since rDTx and rQDTx also had similar biological activities. We also synthesized and expressed a mutant of the DTx gene in which the lysine triplet 28–30 was changed into Ala-Ala-Gly. The two resulting recombinant isoforms exhibited only small decreases in biological activity, excluding the possibility that the positively charged lysine triplet 28–30 of DTx is directly involved in the toxin functional site.

Crystallization and X-ray Diffraction Study of the Streptomyces K15 Penicillin-binding dd-Transpeptidase

The 262 amino acid residue long dd -transpeptidase/penicillin-binding protein of Streptomyces K15 has been crystallized at room temperature by using the hanging drop vapour diffusion technique. The crystals belong to the orthorhombic space group P212121, with unit cell parameters a = 46·4 Å, b = 54·1 Å and c = 108·3 Å. They contain one protein molecule per asymmetric unit and diffract to about 1·9 Å. X-ray data have been collected to 2·0 Å from a native crystal. The previously published amino acid sequence of the protein has been corrected at positions 71, 72, 113, 114 and 156.

The organization of the beta-globin gene of the bivalve mollusc Anadara trapezia and its evolutionary relationship to other invertebrate and vertebrate globin genes.

Three pairs of oligonucleotide primers based on partial DNA and amino acid sequences were used in a combination of PCR experiments to amplify the beta-globin gene of the bivalve mollusc Anadara trapezia. The sequence of 2,139 bp presented contains the whole of the beta-globin gene with the exception of the 5' flanking sequence. This gene possesses the three-exon-and-two-intron gene structure typical of vertebrate globin genes but the lengths of the introns (762 bp and 690 bp, respectively) are only approximately half the size of those present in a beta-variant gene previously characterized from this organism. The encoded amino acid sequence shows two changes when compared to the previously published amino acid sequence.

Primary Structure of Human Liver Glycogen Synthase Deduced by cDNA Cloning

The cDNA for human liver glycogen synthase was isolated by screening a human liver cDNA library constructed in λgt11. The full cDNA was 2912 bp in length. It coded for a protein of 703 amino acid residues with a molecular mass of 80.9 kDa. The number of amino acids was identical to and the deduced amino acid sequence homology was 92% that of the rat liver enzyme. The human and rat liver glycogen synthases are truncated by 34 amino acids compared to the human muscle enzyme, and by 32 amino acids compared to the rabbit muscle enzyme. The amino acid similarity between human liver and human muscle glycogen synthase was only 69%. It was least similar in the N and C terminal regions of the molecule. Two highly conserved regions are present in all published amino acid sequences for glycogen synthase, including those of the two yeast enzymes. These regions include the amino acid sequences from 201 to 400 and 501 to 600. This high conservation suggests that the catalytic site and the glucose-6-P and nucleotide allosteric sites are included in these regions.

Local Conformational Changes of Vitronectin upon Adsorption on Glass and Silane Surfaces

The conformation of vitronectin (Vn) in solution and adsorbed to hydrophilic and hydrophobic glass was studied using the polarity-sensitive fluor acrylodan. Free sulfhydryl groups of vitronectin were labeled with acrylodan under nondenaturing conditions. The number and location of the free sulfhydryl groups were determined by cleavage with either formic acid or cyanogen bromide followed by polyacrylamide gel electrophoresis. Based upon published amino acid sequences of Vn, the fluorescence of acrylodan-labeled Vn (Ac-Vn) fragments is consistent with free sulfhydryls being located at cysteine residues 196 and 274. Conformational changes upon adsorption on glass and silanized glass surfaces placed the free sulfhydryl residues in a more hydrophobic environment than was observed when Vn was in PBS solution. Small but statistically significant quenching of Ac-Vn fluorescence with iodide could be explained in terms of a two-site model. Results of this study suggest that the domains surrounding the free sulfhydryl groups of vitronectin experience different environments in solution and adsorbed to surfaces.

Production of monoclonal antibodies recognising different epitopes present on insulin-like growth factor 1.

Monoclonal antibodies (MAbs) were generated against recombinant human insulin-like growth factor 1 (IGF-1) by fusion of NS-1 myeloma cells with spleen cells from BALB/c X DBA mice immunised with recombinant IGF-1 and synthetic peptide sequences derived from the published amino acid sequence of IGF-1. MAbs were produced that recognised four distinct epitopes including two defined segments of the C and D domains. All MAbs were IgM mouse immunoglobulins. These results indicate the feasibility of producing MAbs to highly conserved proteins.

Thimet oligopeptidase: similarity to ‘soluble angiotensin II-binding protein’ and some corrections to the published amino acid sequence of the rat testis enzyme

The deduced amino acid sequence of pig liver soluble angiotensin II-binding protein [Sugiura, Hagiwara and Hirose (1992) J. Biol. Chem. 267, 18067-18072] is similar over most of its length to that reported for rat testis thimet oligopeptidase (EC 3.4.24.15) by Pierotti, Dong, Glucksman, Orlowski and Roberts [(1990) (Biochemistry 29, 10323-10329]. We have found that homogeneous rat testis thimet oligopeptidase binds angiotensin II with the same distinctive characteristics as the pig liver protein. Analysis of the nucleotide sequences reported for the two proteins pointed to the likelihood that sequencing errors had caused two segments of the amino acid sequence of the rat protein to be translated out of frame, and re-sequencing of selected parts of the clone (kindly provided by the previous authors) confirmed this. The revised deduced amino acid sequence of rat thimet oligopeptidase contains 687 residues, representing a protein of 78,308 Da, and is more closely related to those of the pig liver protein and other known homologues of thimet oligopeptidase than that described previously.

The relationships between transketolase, yeast pyruvate decarboxylase and pyruvate dehydrogenase of the pyruvate dehydrogenase complex

The amino acid sequences of four thiamine pyrophosphate-requiring enzymes were aligned with the published amino acid sequence of the transketolase of Hansenula polymorpha. Sequences of the combined α and β subunits of the E 1 enzyme of the pyruvate dehydrogenase complexes of Homo sapiens and Bacillus stearothermophilus aligned well with the transketolase while the E, of the pyruvate dehydrogenase complex of Escherichia coli aligned easily provided a non-aligning segment of 77 amino acids was omitted. The non-acetylating pyruvate decarboxylase of Saccharomyces cerevisiae could only be aligned if the sequence was cut in two with the C-terminus corresponding to the N-terminus of the other TPP-dependent enzymes. Using the published 2.5 Å resolution of the X-ray crystal structure of rSaccharomyces cerevisiae transketolase as a template we show that a hydrophobic region of the β-subunit of the PDH E 1 αβ enzymes likely contains a binding site for the thiazolium ring of TPP and key motifs are retained in common by all the TPP-dependent enzymes considered, which are essential for catalysis.

Molecular cloning of PARP (proline/arginine-rich protein) from human cartilage and subsequent demonstration that PARP is a fragment of the NH 2-terminal domain of the collagen α2(XI) chain

We report the molecular cloning of a proline/arginine-rich protein (called PARP) from human cartilage using the polymerase chain reaction (PCR) and degenerate oligonucleotides based on the previously published amino acid sequence of bovine PARP [1]. Subsequently, a reverse transcription-polymerase chain reaction (RT-PCR) was performed with poly(A)-rich RNA from human cartilage using a sense oligonucleotide derived from PARP and an anti-sense oligonucleotide derived from the known sequence of the human collagen α2(XI) chain [2]. Nucleotide sequencing of the PCR product demonstrated that PARP is a fragment of the NH 2-terminal non-collagenous (NC3) domain of the collagen α2(XI) chain.

Purification and properties of 2'-hydroxybenzalpyruvate aldolase from a bacterium that degrades naphthalenesulfonates

2'-Hydroxybenzalpyruvate aldolase catalyzes the cleavage of 2'-hydroxybenzalpyruvate to salicylaldehyde and pyruvate. This reaction is part of the degradative pathways for naphthalene and naphthalenesulfonates by bacteria. 2'-Hydroxybenzalpyruvate aldolase has been purified to homogeneity from a bacterium that degrades naphthalenesulfonates (strain BN6). The enzyme has a molecular weight of about 120,000 and is composed of identical subunits with a molecular weight of about 38,500. Thus the enzyme appears to exist as a trimeric oligomer. The NH2-terminal amino acid sequence did not show significant homology to other published amino acid sequences. Extensive loss of enzyme activity occurred when the enzyme was incubated with 2'-hydroxybenzalpyruvate in the presence of sodium borhydride. This suggested the intermediate formation of a stable Schiff base between enzyme and substrate. 2'-Hydroxybenzalpyruvate aldolase was inhibited by p-chloromercuribenzoate and by the reaction product salicylaldehyde. The enzyme converted 2'-hydroxybenzalpyruvate, 2',4'- and 2',6'-dihydroxybenzalpyruvate.

Biochemical and immunocytochemical characterization of antipeptide antibodies to a cloned GluR1 glutamate receptor subunit: Cellular and subcellular distribution in the rat forebrain

Antibodies were made to synthetic peptides corresponding to residues 253–367, 757–771 and 877–889 of the published amino acid sequence of the rat brain glutamate receptor GluR1 subunit [Hollmann et al. (1989) Nature 342, 643–648]. The peptides were synthesized both as multiple copies on a branching lysyl matrix (multiple antigenic peptides) and conventional linear peptides using solid-phase synthesis. Rabbits were immunized with these peptides either without conjugation (multiple antigenic peptides) or following coupling to ovalbumin with glutaraldehyde (monomeric peptides). The antibodies from immune sera were then purified by affinity chromatography using reactigel coupled monomeric peptides. All the rabbits produced good antipeptide responses, and were characterized by immunoprecipitation ofsolubilized α-amino-3-hydroxy-5-methylisoxazole-4-propionate and kainate binding activity and by their staining patterns on immunoblots. Antibody to peptide 253–267 specifically immunoprecipitated 12 ± 3, 50 ± 3 and 44 ± 4% of solubilized α-amino-3-hydroxy-5-methylisoxazole-4-propionate binding activity from cortex, hippocampus and cerebellum, respectively. Under identical conditions, antibody against the 877–889 peptide removed 23 ± 4, 9 ± 4 and 15 ± 9% of α-amino-3-hydroxy-5-methylisoxazole-4-propionate binding sites from these areas. On immunoblots of rat brain membrane samples separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, antibodies labelled a 105,000 mol. wt immunoreactive band. GluR1 was immunoaffinity-purified using subunit-specific antibodies against both N-terminal (253–267) and C-terminal (877–889) residues, covalently attached to protein A-agarose. Analysis of the purified product from each column showed a major immunoreactive band, recognized by both sera at 105,000 mol. wt and silver staining identified the same major protein. After exhaustive immunoprecipitation of solubilized membrane samples with antibody against the C-tenninal of the subunit, a subpopulation of GluR1 was labelled with antibodies specific for the N-terminal part of the receptor. These observations suggest that the GluR1 subunit consists of at least two isoforms possessing a common N-terminal region but a distinct C-terminus. Immunocytochemistry, using immunoperoxidase staining, was performed for the GluRl subunit in rat forebrain with antisera raised against the N-terminal (253–267) and the C-terminal parts (877–889) of the molecule. Both antisera gave a similar distribution of immunoreactivity at the light-microscopic level. Immunoreactivity for the GluR1 subunit was selectively distributed throughout the rat forebrain. The hippocampus, septum, amygdala and olfactory bulb exhibited the strongest immunoreactivity. Immunoreactivity was found in cell bodies and processes of neurons and also in tanicytes, a specialized glial cell type of the hypothalamus. The CA1 region of the hippocampus was particularly rich in GluR1 subunit. Electron-microscopic examination of the CA1 area revealed that immunoreactivity for the GluR1 subunit was present within the endoplasmic reticulum of neurons, at a majority of type I synapses established on dendritic spines, and also at extrasynaptic sites along the dendritic membrane of the pyramidal cells. Immunoreactivity obtained with the antiserum to the N-terminal part (253–267) detected epitopes at the extracellular face of plasma membrane, whereas the antiserum raised against the C-terminal part of the GluR1 subunit (877–889) recognized epitopes at the intracellular face of postsynaptic membranes. The results demonstrate that the antisera selectively react with GluR1 subunit(s) of the α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor. This subunit is distributed in an area and cell type specific manner in the forebrain and is present at synapses assumed to use excitatory amino acids as transmitters. Immunocytochemistry at the subcellular level suggests that the C-terminus of the subunit is located at the cytoplasmic face of the synaptic membrane contrary to the currently held model.

Purification of Calreticulin-like Protein(s) from Spinach Leaves

In a search for the plant equivalent of calsequestrin or calreticulin, the high capacity, low affinity Ca 2+ binding proteins of muscle and non-muscle cells thought to play important roles in Ca 2+ storage, we purified two Ca 2+-binding proteins from spinach leaves. The proteins had apparent molecular weights of 55 and 53 kDa. On Western blot, they did not react either with anti-rabbit skeletal muscle, anti-dog cardiac muscle calsequestrin or anti-rabbit or anti-rat liver calreticulin antibodies, indicating that they were antigenically distinct. Periodic acid Schiff staining (PAS) revealed that the larger protein was glycosylated while the 53 kDa one was PAS-negative. When the proteins were subjected to NH 2-terminus amino acid sequencing, the 55 and 53 kDa proteins turned out to be identical, thus probably representing different isoforms of the same protein. Comparison with published amino acid sequences of calreticulin reveals regions of similarity indicating that the plant Ca 2+-binding proteins probably belong to the calreticulin family.

Cloning of the porcine Calbindin-D9k complementary deoxyribonucleic acid by anchored polymerase chain reaction technique.

The Calbindin-D9k (CaBP-9k) is a cytosolic calcium binding protein expressed in the mammalian intestine, placenta, and uterus. The protein is probably involved in calcium transport across the intestinal and placental epithelia. In uterus, a function in controlling myometrial activity involving intracellular calcium has been postulated. The amino acid sequence of the porcine CaBP-9k has been determined from intestine. The cDNAs for the bovine, murine, and rat CaBP-9k have been cloned. The objective of this study was the cloning of the porcine cDNA encoding the CaBP-9k. We performed the anchored polymerase chain reaction (PCR) technique using rat and bovine cDNA sequence-derived primers for amplification of intestinal cDNA. Both 5' and 3' amplification products were cloned and sequenced. The sequences revealed the full-length cDNA encoding the porcine CaBP-9k, coding region for 79 amino acids, 57 nucleotides 5' and 149 nucleotides 3' noncoding region. The inferred amino acid sequence is identical to the published amino acid sequence, except for one residue. The porcine CaBP-9k cDNA is 82.8% and 69.1% homologous with the bovine and rat sequences, respectively. Both bovine and porcine cDNAs contain a stretch of approximately 50 nucleotides not found in the rat sequence. Northern analysis showed a 600 nucleotide transcript in intestine, kidney, and uterus.

Synthetic peptides representing epitopes of outer membrane protein F of Pseudomonas aeruginosa that elicit antibodies reactive with whole cells of heterologous immunotype strains of P. aeruginosa.

By using the published amino acid sequence for mature outer membrane protein F of Pseudomonas aeruginosa, a computer-assisted analysis was performed to identify sites with potential as surface-exposed, antigenic regions located throughout the length of the protein molecule. Synthetic peptides 13 to 15 amino acid residues in length were synthesized for 10 such regions. Mice were immunized with each of the 10 synthetic peptides conjugated to keyhole limpet hemocyanin. An enzyme-linked immunosorbent assay (ELISA) of the antisera was performed by using each of the synthetic peptides as the ELISA antigen to verify that immunoglobulin G (IgG) antibodies capable of reacting with the peptide used as immunogen were elicited by each peptide. Each of the antipeptide antisera was screened for the presence of IgG antibodies that could bind to the surface of intact cells of strains representing the seven heterologous Fisher-Devlin immunotypes of P. aeruginosa by use of an ELISA with whole cells of the various strains as the ELISA antigen. Three peptides elicited antibodies capable of reacting with whole cells of all seven immunotype strains. Peptide 10, corresponding to amino acid residues 305 to 318, elicited whole-cell-reactive antibodies at high titers. Peptide 9, corresponding to amino acid residues 261 to 274, elicited whole-cell-reactive antibodies at more intermediate titers. Peptide 7, corresponding to amino acid residues 219 to 232, elicited such antibodies only at low titers. The carboxy-terminal portion of the mature protein appears to be the immunodominant portion. In particular, peptides 10 (NATAEGRAINRRVE) and 9 (TDAYNQKLSERRAN) appear to have potential for use as immunogens in a synthetic vaccine for immunoprophylaxis against infections caused by P. aeruginosa. Antisera from mice immunized with either peptide 9 or 10 mediated opsonophagocytic uptake by human polymorphonuclear leukocytes of wild-type cells of P. aeruginosa but exhibited no opsonic activity against a protein F-deficient mutant of P. aeruginosa.