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PubMed2002

Molecular cloning and expression of the porcine trigeminal ganglion cDNA encoding a 5-ht(1F) receptor.

Using a combination of reverse transcription polymerase chain reaction (RT-PCR) and inverse-PCR techniques, we amplified, cloned and sequenced a full-length porcine 5-hydroxytryptamine 1F (5-ht(1F)) receptor complementary DNA (cDNA) derived from porcine trigeminal ganglion. Sequence analysis revealed 1101 base pairs (bp) encoding an open reading frame of 366 amino acids showing a high similarity (>90%) with the 5-ht(1F) receptor sequences from other species, including human. The recombinant porcine 5-ht(1F) receptor was expressed in African green monkey kidney cell lines (COS-7 cells) and its ligand binding profile was determined using [3H]5-HT. The affinities of several agonists (LY334370 (5-(4-fluorobenzoyl)amino-3-(1-methylpiperidin-4-yl)-1H-indole fumarate)>CP122638 (N-methyl-3 [pyrrolidin 2(R)-yl methyl]-1H-indol-5-ylmethyl sulphonamide)=naratriptan =5HT>eletriptan>sumatriptan>frovatriptan =avitriptan>dihydroergotamine>zolmitriptan>5-carboxamidotryptamine>rizatriptan>alniditan=donitriptan>L694247 (2-[5-[3-(4-methylsulphonylamino)benzyl-1,2,4-oxadiazol-5-yl]-1H-indole-3-yl] ethylamine) and putative antagonists (methiothepin>GR127935 (N-[4-methoxy-3-(4-methyl-1-piperazinyl) phenyl]-2'-methyl 4'-(5-methyl-1,2,4-oxadiazol-3-yl) [1,1-biphenyl]-4-carboxamide hydrochloride)>ritanserin>SB224289 (2,3,6,7-tetrahydro-1'-methyl-5-[2'-methyl-4'(5-methyl-1,2,4-oxadiazol-3-yl) biphenyl-4-carbonyl] furo [2,3-f] indole-3-spiro-4'-piperidine hydrochloride)>BRL155572 ([1-(3-chlorophenyl)-4-[3,3-diphenyl (2-(S,R) hydroxypropanyl)piperazine] hydrochloride)>ketanserin=pindolol) correlated highly with those described for the recombinant human 5-ht(1F) receptor (Spearman correlation coefficient; r(s)=0.942). Nevertheless, as compared to the human homologue, some triptans (i.e. sumatriptan, zolmitriptan and rizatriptan) displayed a 10- to 15-fold lower affinity for the porcine 5-ht(1F) receptor. Using RT-PCR technique, the expression of porcine 5-ht(1F) receptor mRNA was observed in cerebral cortex, trigeminal ganglion and several blood vessels, but not in skeletal muscles. In conclusion, we have cloned and established the amino acid sequence and ligand binding profile of the porcine 5-ht(1F) receptor as well as the distribution of its mRNA. This information may be helpful in exploring the role of 5-ht(1F) receptor in physiological processes and diseases, such as migraine.

Amino Acid Sequence↗

PubMed2000

A missense mutation in the heavy subunit of gamma-glutamylcysteine synthetase gene causes hemolytic anemia.

gamma-Glutamylcysteine synthetase (GCS) catalyzes the initial and rate-limiting step in the biosynthesis of glutathione. gamma-GCS consists of a heavy and a light subunit encoded by separate genes. Hereditary deficiency of GCS has been reported in 6 patients with hemolytic anemia and low erythrocyte levels of glutathione and gamma-glutamylcysteine. In addition, 2 patients also had generalized aminoaciduria and developed neurologic symptoms. We have examined a Dutch kindred with 1 suspected case of GCS deficiency. The proband was a 68-year-old woman with a history of transient jaundice and compensated hemolytic anemia. One of her grandchildren was also GCS deficient; he was 11 years old and had a history of neonatal jaundice. The enzyme defect was confirmed and GCS activity was found to be less than 2% of normal in the erythrocytes of both patients. The complementary DNA (cDNA) for the heavy subunit of GCS was sequenced in these patients and in several members of the family. The proband and her GCS- deficient grandson were identified as homozygous for a 473C-->T substitution, changing codon 158 from CCC for proline into CTC for leucine. Several family members with half-normal GCS activity in their erythrocytes were heterozygous for the mutation.

Aged↗

PubMed2000

Avian galanin: cloning of complementary DNAs and characterization of transcripts in different tissues.

Avian galanin was first isolated from the chicken intestine, and subsequently from the quail oviduct. Avian galanin is a 29-residue peptide including an amidated threonine at the C-terminus and differs at several positions from the C-terminal part of mammalian galanins. In contrast to extensive mammalian studies, no information is available on the structure of precursor molecule of avian galanin. In this study, therefore, we conducted complementary DNA (cDNA) cloning of the avian galanin gene from quail brain RNA using degenerated 3'RACE and 5'RACE techniques. A cloned cDNA for avian galanin contained an open reading frame consisting of 117 amino acids which had overall amino acid homology of 63%, 60%, 54%, 58%, and 62% with bovine, human, mouse, porcine, and rat galanins, respectively. Another cDNA containing a 69-nucleotide insertion, which gave an additional 23 amino acids to mature avian galanin, was also cloned, suggesting the presence of two transcripts by alternative splicing. Northern blot analysis revealed that avian galanin mRNA was expressed, as a shorter transcript, in the quail brain, ovary, and intestine, unlike the liver and oviduct. A larger mRNA of avian galanin may be further expressed only in the ovary.

Amino Acid Sequence↗

PubMed2004

Isolation of cDNA of novel cytochrome P450 1B gene, CYP1B2, from Carp (Cyprinus carpio) and its induced expression in gills.

Cytochrome P450 (CYP) enzymes constitute a multigene family of many endogenous and xenobiotic substances. The CYP1 family is of particular interest in environmental toxicology because its members are dominant in the metabolism of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and aryl amines. A new complementary DNA of the CYP1B subfamily encoding CYP1B2 was isolated from carp liver after intraperitoneal injection with 3-methylcholanthrene (3-MC). The obtained full-length cDNA contained a 5'noncoding region of 161 bp, an open reading frame of 1593 bp coding for 530 amino acids and a stop codon, and a 3'noncoding region of 1457 bp. The predicted molecular weight of the protein was approximately 60.2 kDa. The deduced amino acid sequence of this cDNA was 91% similar to that of our previously reported carp CYP1B1; its similarities with those of the reported CYP1B1s of teleosts and mammals were 60.8, 54.4, 50.8, and 51.4% for plaice, human, rat, and mouse, respectively. The phylogenetic tree of fish and mammalian CYP1 sequences constructed by the protein maximum-likelihood method suggested a relatively recent divergence of CYP1B2 from CYP1B1 in the ancestor of carp and closely related species. Despite the structural similarity of CYP1B2 with CYP1B1, which showed induced expression in 3-MC-treated liver, intestine, and gills with marked constitutive expression in gills, CYP1B2 revealed induced expression in gills but not in liver or intestine, and no detectable constitutive expression in the tissues studied.

Animals↗

PubMed1994

Isolation of differentially expressed sequence tags from human breast cancer.

Identification of quantitative changes in gene expression that occur in the malignant mammary gland, if sufficiently characterized, may yield novel molecular markers which may be useful in the diagnosis and treatment of human breast cancer. Using modifications of a previously documented technique, the differential display polymerase chain reaction, we describe the isolation of differentially expressed sequence tags, short complementary DNA fragments corresponding to mRNAs that are differentially expressed in breast cancer biopsies, as compared to normal breast tissue controls. Direct sequencing and expression analysis of two sequence tags demonstrate that they represent sequences which are overexpressed in a number of breast carcinoma cell lines. A paradigm for generating a catalogue of these sequence tags is discussed.

Base Sequence↗

PubMed1997

Molecular cloning and functional expression of cDNA encoding the pig plasma phospholipid transfer protein.

Humans and the pig show marked similarities in lipoprotein metabolism; therefore, the pig has been used as a model in numerous nutritional studies. Pig plasma displays no activity of cholesteryl ester transfer protein (CETP), which is known to be responsible for half of the phospholipid mass transfer in human plasma, the other half being accounted for by the plasma phospholipid transfer protein (PLTP). This makes the pig an ideal subject for the study of PLTP structure and function. Here we report the molecular cloning of pig PLTP and the eukaryotic cell expression of its complementary DNA. Pig PLTP was found to share 93% amino acid sequence identity with human PLTP and 81% with mouse PLTP. Tissue expression of PLTP mRNA was examined by a method based on reverse transcription-polymerase chain reaction (RT-PCR) and solid-phase minisequencing in nine pig tissues. The highest PLTP mRNA levels were found in the pancreas, brain, lung, and liver. Medium from COS-1 cells expressing PLTP possessed phospholipid transfer activity, and the secreted recombinant PLTP was detectable by Western blotting in the culture supernatant. A mutant protein with a substitution of Cys at position 22 by Arg was found to display impaired secretion into growth medium indicating a role for cysteines in the correct folding of PLTP. This study forms the basis for future work on the structure-function relationships in pig PLTP.

Amino Acid Sequence↗

PubMed1998

Molecular identification of the lobster muscle protein tropomyosin as a seafood allergen.

Crustaceans are a major cause of seafood allergy. Recent studies have identified tropomyosin as the major allergen in shrimp. However, such data are lacking in other crustaceans. In the present study lobster allergens were identified and characterized by molecular cloning, sequencing, and expression. An IgE-reactive complementary DNA clone of 2 kilobase pairs (kb) was identified by screening an expression library of the spiny lobster Panulirus stimpsoni using sera from subjects with crustacean allergy. Expression and sequencing of this clone showed that it has an opening reading frame of 274 amino acids, coding for a 34-kDa protein designated as Pan s I. In addition, we expressed the fast muscle tropomyosin from the American lobster Homarus americanus and found that this protein, coined Hom a I, was also recognized by IgE from patients with crustacean allergies. The deduced amino acid sequences of Pan s I and Hom a I, which are the first identified lobster allergens, show significant homology to shrimp tropomyosin. Sera from subjects with crustacean allergies, when preabsorbed with recombinant proteins Pan s I or Hom a I, lost their IgE reactivity to muscle extract of P. stimpsoni and H. americanus. Preincubation of crustacean allergy sera with the recombinant shrimp tropomyosin Met e I also removed their IgE reactivity to lobster muscle extracts. The results suggest that patients with allergic reactions to crustaceans have common and possibly cross-reactive IgE-reactive epitopes in lobster and shrimp.

Allergens↗

PubMed1997

Analysis of a sequenced cDNA library from multiple sclerosis lesions.

To identify genes that are expressed in MS pathogenesis, we have analyzed a normalized cDNA library made from mRNA obtained from CNS lesions of a patient with primary progressive MS. Complementary DNA clones obtained from this library were subjected to automated DNA sequencing to generate expressed sequence tags. Analysis of this MS cDNA library revealed the presence of 54 cDNAs that were associated with immune activation and indicated the presence of an ongoing inflammatory response with evidence of both cell-mediated and humoral immune responses. The surprising finding was that 16 of the cDNAs encoded autoantigens associated with seven other autoimmune disorders, while only three of these 16 autoantigen cDNAs were present in a similarly constructed adult brain library. Such aberrant autoantigen expression could provide a source of secondary autoimmune stimulation that could contribute to the ongoing inflammatory response in MS. In addition, two cDNAs were found that mapped to a known MS susceptibility locus (5p14-p12): one encoded an excitatory amino acid transporter and the other a human homologue of the Drosophila disabled gene. This approach to the molecular biology of MS pathogenesis may help to illuminate previously unappreciated aspects of this disease.

Cloning, Molecular↗

PubMed1996

Cloning and characterization of a glycogen synthase cDNA from human endometrium.

One major human uterine response to post-ovulatory progesterone is the accumulation of glycogen by the endometrium. A temporally related increase in glycogen synthase activity has been documented, but the isozyme responsible has not yet been identified. We have amplified a glycogen synthase (GS) complementary DNA (cDNA) from human endometrium by reverse transcription-polymerase chain reaction (RT-PCR). Overlapping clones of the PCR products provided a cDNA that is 3534 base pairs (bp) long, including a 22-bp poly(A)+ tail, and an open reading frame that encodes a 737 amino acid protein with a molecular weight of 83936. This cDNA is almost identical to that of human striated muscle GS. Differences include a double nucleotide substitution at 1983-1984 and five single nucleotide substitutions located, respectively, at positions 379, 2457, 2470, 2477, and 2553. These differences only alter the predicted amino acid sequence from that of the striated muscle protein by a single substitution at position 608. A 5'-end fragment plus an internal fragment of human myometrial GS cDNA were also analysed and were shown to have identity with the endometrial GS cDNA. Northern blot hybridization, using a human muscle-derived cDNA probe, detected the presence of a 4.0-kb GS messenger RNA (mRNA) in the endometrium and myometrium. Our results establish that the GS of human Mullerian tissues is, essentially, identical to that reported for human striated muscle.

Amino Acid Sequence↗

PubMed1998

Complete sequence of p53 gene in 20 patients with lung cancer: comparison with chemosensitivity and immunohistochemistry.

In this study the entire p53 complementary DNA has been sequenced in 20 non-small cell lung carcinomas (NSCLC) and the results correlated with chemosensitivity, immunohistochemistry and clinical data. Ten patients had mutations in p53, 8 missense mutations and 2 nonsense mutations. The method discovered two mutations never described previously and two other mutations that have never been described before in connection with NSCLC tumours. Chemosensitivity data, according to a short-term assay (FMCA), indicated that tumours with p53 mutation were more resistant to cisplatin and cyclophosphamide. Immunohistochemical studied demonstrated a 70% concordance between over-expression of p53 protein and mutation in p53. No conclusions or trends could be drawn from the immunohistochemical studies of Bcl-2 and Bax.

Adult↗

PubMed1994

Isolation of maltose-regulated genes from the hyperthermophilic archaeum, Pyrococcus furiosus, by subtractive hybridization.

The hyperthermophilic archaeum, Pyrococcus furiosus, utilizes maltose as a preferred carbon source for growth. 32P-labeled complementary DNA (cDNA) probes representing maltose-regulated genes were obtained by a subtractive hybridization procedure that minimized retrieval of ribosomal RNA (rRNA) sequences during screening. Genomic DNA clones were isolated by positive hybridization to these probes. Genes whose expression varied both in the level of transcription, relative to rRNA, as well as in the degree of regulation were obtained; the extent of regulation varied over a wide range, from as little as fivefold to as high as 50-100-fold. DNA sequence analysis of several of these regulated genes indicated that the subtraction library included gene products required for maltose utilization (e.g., pyruvate dikinase), as well as growth-rate-related genes such as those encoding ribosomal proteins and RNA polymerase subunits. Our approach is applicable to studying gene regulation in organisms that are not amenable to classical genetic techniques.

Archaea↗

PubMed2003

Organization of the shrimp vitellogenin gene: evidence of multiple genes and tissue specific expression by the ovary and hepatopancreas.

Vitellogenin is the major egg yolk protein synthesized in female shrimp during gonad maturation. Although there are several reports for the cloning of vitellogenin complementary DNA (cDNA) in different crustaceans, little is known of the gene organization of this protein. This study reports the first cloning and characterization of a full-length gene encoding the vitellogenin precursor from the shrimp Metapenaeus ensis. By genomic DNA library screening, six different lambda clones were isolated using shrimp partial gene sequence as probe. Initial DNA sequence determination revealed that these clones are derived from different genes with coding sequence similar to other crustacean vitellogenins. Two of these clones were used for further analysis. One of the lambda clones (lambda 3.3) carries most of the coding sequence that correspond to the M. ensis vitellogenin gene (MeVg1) and the other clone (lambda 8.3) carries a smaller portion of the coding sequence of a different vitellogenin gene (MeVg2). The lambda 3.3 clone was chosen for further characterization. To clone the remaining 5' end upstream promoter region, 5' untranslated region and the remaining coding sequence of MeVg1, a polymerase chain reaction (PCR)-based gene walking approach was used. Subsequently, a PCR clone with overlapping sequence identical to the genomic clone was obtained and the organization of MeVg1 gene was constructed. The MeVg1 gene consists of 15 exons and 14 introns spanning approximately 10 kb. Several potential cleavage sites were identified from the deduced vitellogenin precursor. Cleaving of the precursor in these sites would result in the production of several vitellogenin subunits. To clone the cDNA for the vitellogenin, 5' and 3' rapid amplification of cDNA ends was performed using ovary cDNA of the shrimp. A 4.4 kb 5' cDNA clone and a 4 kb 3' end cDNA clone were isolated. The size of the reconstructed cDNA for M. ensis Vg is 7.97 kb and consists of the longest open reading frame of 7776 bp. Unlike the vitellogenin precursor of most insects and vertebrates, the deduced vitellogenin precursor lacks the polyserine domain important for receptor-mediated endocytosis. Phylogenetic analysis revealed a closer relationship of the MeVg1 with other crustacean vitellogenins but distantly related to other invertebrate and vertebrate vitellogenins. By reverse transcription-PCR, we have demonstrated that the shrimp MeVg1 gene is expressed only in the ovary and hepatopancreas while the MeVg2 gene is expressed exclusively in the hepatopancreas. In conclusion, the shrimp ovary also contribute significantly in the production of vitellogenin at transcription level and the gene organization of the shrimp protein may provide an insight in the evolution of this group of important proteins.

Amino Acid Sequence↗

PubMed1997

Cloning and expression of a PR5-like protein from Arabidopsis: inhibition of fungal growth by bacterially expressed protein.

Pathogenesis-related (PR)-5 proteins are a family of proteins that are induced by different phytopathogens in many plants and share significant sequence similarity with thaumatin. We isolated a complementary DNA (ATLP-3) encoding a PR5-like protein from Arabidopsis which is distinct from two other previously reported PR5 cDNAs from the same plant species. The predicted ATLP-3 protein with its amino-terminal signal sequence is 245 amino acids in length and is acidic with a pl of 4.8. The deduced amino acid sequence of ATLP-3 shows significant sequence similarity with PR5 and thaumatin-like proteins from Arabidopsis and other plants and contains a putative signal sequence at the amino-terminus. The expression of ATLP-3 and a related gene (ATLP-1) that we previously isolated from Arabidopsis was induced by pathogen infection and salicylic acid, a known inducer of pathogenesis-related genes. Southern blot analysis indicates that the ATLP-1 and ATLP-3 are coded by single-copy genes. To study the effect of ATLP-1 and ATLP-3 proteins on fungal growth, the cDNA regions corresponding to putative mature protein were expressed in Escherichia coli and the cDNA encoded proteins were purified. ATLP-1 and ATLP-3 proteins cross-reacted with anti-osmotin and anti-zeamatin antibodies. ATLP-3 protein showed antifungal activity against several fungal pathogens suggesting that ATLP-3 may be involved in plant defense against fungal pathogens.

Amino Acid Sequence↗

PubMed2001

Genomic analysis of clinical samples with serologic ABO blood grouping discrepancies: identification of 15 novel A and B subgroup alleles.

Since the cloning in 1990 of complementary DNA corresponding to messenger RNA transcribed at the blood group ABO locus, polymorphisms and phenotype-genotype correlations have been reported by several investigators. Exons 6 and 7, constituting 77% of the gene, have been analyzed previously in samples with variant phenotypes but for many subgroups the molecular basis remains unknown. This study analyzed 324 blood samples involved in ABO grouping discrepancies and determined their ABO genotype. Samples from individuals found to have known subgroup alleles (n = 53), acquired ABO phenotypes associated with different medical conditions (n = 65), probable chimerism (n = 3), and common red blood cell phenotypes (n = 109) were evaluated by ABO genotype screening only. Other samples (n = 94) from apparently healthy donors with weak expression of A or B antigens were considered potential subgroup samples without known molecular background. The full coding region (exons 1-7) and 2 proposed regulatory regions of the ABO gene were sequenced in selected A (n = 22) or B (n = 12) subgroup samples. Fifteen novel ABO subgroup alleles were identified, 2 of which are the first examples of mutations outside exon 7 associated with weak subgroups. Each allele was characterized by a missense or nonsense mutation for which screening by allele-specific primer polymerase chain reaction was performed. The novel mutations were encountered in 28 of the remaining 60 A and B subgroup samples but not among normal donors. As a result of this study, the number of definable alleles associated with weak ABO subgroups has increased from the 14 previously published to 29.

ABO Blood-Group System↗

PubMed2000

Molecular analysis of delta-aminolevulinate dehydratase deficiency in a patient with an unusual late-onset porphyria.

Cloning, expression, and genotype studies of the defective gene for delta-aminolevulinate dehydratase (ALAD) in a patient with an unusual late onset of ALAD deficiency porphyria (ADP) were carried out. This patient was unique in that he developed the inherited disease, together with polycythemia, at the age of 63. ALAD activity in erythrocytes of the patient was less than 1% of the normal control level. ALAD complementary DNA (cDNA) isolated from the patient's Epstein-Barr virus (EBV)-transformed lymphoblastoid cells had 2 base transitions in the same allele, G(177) to C and G(397) to A, resulting in amino acid substitutions K59N and G133R, respectively. It has been verified that the patient had no other ALAD mutations in this and in the other allele. By restriction fragment length polymorphism (RFLP) analysis, all family members of the proband who had one-half ALAD activity compared with the ALAD activity of the healthy control were shown to have the same set of base transitions. Expression of ALAD cDNA in CHO cells revealed that K59N cDNA produced a protein with normal ALAD activity, while G133R and K59N/G133R cDNA produced proteins with 8% and 16% ALAD activity, respectively, compared with that expressed by the wild type cDNA. These findings indicate that while the proband was heterozygous for ALAD deficiency, the G(397) to A transition resulting in the G133R substitution is responsible for ADP, and the clinical porphyria developed presumably due to an expansion of the polycythemic clone in erythrocytes that carried the mutant alad allele.

Age of Onset↗

PubMed1993

Direct RT-PCR amplification of mRNA supported on membranes.

We describe a simple and efficient technique that facilitates the amplification of specific mRNA for cloning and sequencing purposes. An mRNA bound to a small piece of membrane filter is used as a template to synthesize complementary DNA. The product of this reaction is then transferred to a new tube and amplified using a standard PCR protocol. By simple enzymatic treatment, this RNA membrane can be reused as many times as needed with no problems of low yield, mispriming or background. Multiple advantages and different applications can be gained with this procedure. We have been using this technique to characterize a 4.5-kb mRNA from human retinal pigment epithelial cells following identification by Northern blot. According to the size of the PCR amplification products, this mRNA band contains portions of the coding sequence for the Na+K(+)-ATPase beta 1 subunit.

Base Sequence↗

PubMed1993

Molecular cloning of a novel isotype of Mg(2+)-dependent protein phosphatase beta (type 2C beta) enriched in brain and heart.

Two complementary DNA (cDNA) clones (pTK-1 and -2) encoding two distinct isotypes of mouse Mg(2+)-dependent protein phosphatase beta (MPP beta-1 and -2, respectively) were isolated from a melanocyte cDNA library. Although mouse pTK-1 is orthologous to the rat cDNA (JW5) reported previously [Wenk, J., Trompeter, H.I., Pettrich, K.G., Cohen, P.T.W., Campbell, D.G., and Mieskes, G. (1992) FEBS Lett. 297, 135-138], pTK-2 is a novel cDNA clone. It was strongly suggested that the pTK-1 and -2 cDNAs are splicing variants of a single pre-mRNA. The difference in the amino acid sequences between MPP beta-1 and -2 was observed only at the carboxy-terminal regions. Both the recombinant MPP beta-1 and -2 expressed in Escherichia coli cells were immunoreactive to an anti-MPP beta antibody and exhibited Mg(2+)-dependent and okadaic acid-insensitive protein phosphatase activities with similar substrate specificities. Although the mRNA of MPP beta-1 was expressed ubiquitously in various mouse tissues, that of MPP beta-2 was expressed exclusively in brain and heart. These results suggest the difference in the physiological roles of these two enzyme isotypes.

Amino Acid Sequence↗

PubMed2002

The African trypanosome cyclophilin A homologue contains unusual conserved central and N-terminal domains and is developmentally regulated.

We have cloned and characterized the homologue of cyclophilin A (CypA) from Trypanosoma brucei brucei, Trypanosoma congolense, Trypanosoma evansi and Trypanosoma vivax. The 1-kilobase African trypanosome CypA complementary DNA contains an open reading frame of 531 base pairs, corresponding to 177 amino acids with a calculated molecular weight of 18,700. The CypA gene is present at one copy/haploid genome in T. brucei, T. congolense and T. vivax and is located on large chromosomes (>3 Mb) in T. brucei. CypA is differentially transcribed in African trypanosomes and is localized in the cytosol as well as in the flagellum. It is also detected in the supernatant of in vitro cultivated parasites. The African trypanosome CypA is unique due to a ten amino acid residue N-terminus extension and a block that includes a three amino acid insertion around position 100 that might result in a differently structured surface. Wild-type recombinant CypA and several mutants were over-expressed in Escherichia coli and purified to >98% homogeneity. Antisera from cattle immunized with a trypanosome fraction containing immunosuppressive activity react strongly against CypA. These data indicate that trypanosome CypA might play an important role in the establishment and maintenance of infections in susceptible animals.

Amino Acid Sequence↗