scholarly journals Effect of Multiple Mutations in the Hemoglobin- and Hemoglobin-Haptoglobin-Binding Proteins, HgpA, HgpB, and HgpC, ofHaemophilus influenzae Type b

1999 ◽  
Vol 67 (6) ◽  
pp. 2729-2739 ◽  
Author(s):  
Daniel J. Morton ◽  
Paul W. Whitby ◽  
Hongfan Jin ◽  
Zhen Ren ◽  
Terrence L. Stull
Keyword(s):  
Haemophilus Influenzae ◽  
Insertional Mutagenesis ◽  
Binding Proteins ◽  
Affinity Purification ◽  
Triple Mutant ◽  
Gene Encoding ◽  
Purification Method ◽  
Insertional Mutation ◽  
Ofhaemophilus Influenzae ◽  
Complete Deletion

ABSTRACT Haemophilus influenzae requires heme for growth and can utilize hemoglobin and hemoglobin-haptoglobin as heme sources. We previously identified two hemoglobin- and hemoglobin-haptoglobin-binding proteins, HgpA and HgpB, in H. influenzae HI689. Insertional mutation of hgpA andhgpB, either singly or together, did not abrogate the ability to utilize or bind either hemoglobin or the hemoglobin-haptoglobin complex. A hemoglobin affinity purification method was used to isolate a protein of approximately 120 kDa from thehgpA hgpB double mutant. We have cloned and sequenced the gene encoding this third hemoglobin/hemoglobin-haptoglobin binding protein and designate it hgpC. Insertional mutation ofhgpC did not affect the ability of the strain to utilize either hemoglobin or hemoglobin-haptoglobin. An hgpA hgpB hgpC triple mutant constructed by insertional mutagenesis showed a reduced ability to use the hemoglobin-haptoglobin complex but was unaltered in the ability to use hemoglobin. A second class of mutants was constructed in which the entire structural gene of each of the three proteins was deleted. The hgpA hgpB hgpCcomplete-deletion triple mutant was unable to utilize the hemoglobin-haptoglobin complex and showed a reduced ability to use hemoglobin. We have identified three hemoglobin/hemoglobin-haptoglobin-binding proteins in Haemophilus influenzae. Any one of the three proteins is sufficient to support growth with hemoglobin-haptoglobin as the heme source, and expression of at least one of the three is essential for hemoglobin-haptoglobin utilization. Although the three proteins play a role in hemoglobin utilization, an additional hemoglobin acquisition mechanism(s) exists.

scholarly journals hgpB, a Gene Encoding a Second Haemophilus influenzae Hemoglobin- and Hemoglobin-Haptoglobin-Binding Protein

1998 ◽  
Vol 66 (10) ◽  
pp. 4733-4741 ◽  
Author(s):  
Zhen Ren ◽  
Hongfan Jin ◽  
Daniel J. Morton ◽  
Terrence L. Stull
Keyword(s):  
Haemophilus Influenzae ◽  
Double Mutant ◽  
Binding Protein ◽  
Affinity Purification ◽  
Peptide Sequencing ◽  
Gene Encoding ◽  
Reading Frame ◽  
Affinity Isolation ◽  
Directional Cloning ◽  
Frame Bound

ABSTRACT Haemophilus influenzae requires heme for growth and can utilize both hemoglobin and hemoglobin-haptoglobin as heme sources. We previously identified a hemoglobin- and hemoglobin-haptoglobin-binding protein, HgpA, in H. influenzae HI689. Mutation ofhgpA did not affect binding or utilization of either heme source. The hgpA mutant exhibited loss of a 120-kDa protein and increased expression of a 115-kDa protein. These data suggested that at least one other gene product is involved in binding of these heme sources by H. influenzae. A 3.2-kbp PCR product derived from HI689 was cloned. The nucleotide sequence indicated a separate, distinct gene with high homology tohgpA, which would encode a 115-kDa protein. Primers were designed for directional cloning of the structural gene in the correct reading frame. Sonicates of induced Escherichia coliharboring the cloned open reading frame bound both hemoglobin and hemoglobin-haptoglobin. An insertion/deletion mutant of H. influenzae at the newly identified locus, designatedhgpB, was constructed. The 115-kDa protein was not detected in the mutant after affinity purification using biotinylated hemoglobin. An hgpA hgpB double-mutant strain exhibited a reduced ability to utilize hemoglobin-haptoglobin, although it was unaltered in the ability to utilize hemoglobin. Affinity isolation of hemoglobin-binding proteins from the double mutant resulted in isolation of an approximately 120-kDa protein. Internal peptide sequencing revealed this protein to be a third distinct protein, highly homologous to HgpA and HgpB. In summary a second hemoglobin- and hemoglobin-haptoglobin-binding protein of H. influenzae has been identified and characterized, and the presence of an additional protein of similar function has been revealed.

Purification of four gelatin-binding proteins from bovine seminal plasma by affinity chromatography

1987 ◽  
Vol 7 (3) ◽  
pp. 231-238 ◽  
Author(s):  
P. Manjunath ◽  
M. R. Sairam ◽  
J. Uma
Keyword(s):  
Seminal Plasma ◽  
Binding Proteins ◽  
Affinity Purification ◽  
Polyacrylamide Gel Electrophoresis ◽  
Apparent Molecular Weight ◽  
Single Step ◽  
High Yield ◽  
Property A ◽  
Purification Method ◽  
Elution Pattern

Bovine seminal plasma contains three similar acidic proteins, which we have previously designated as BSP-A1, BSP-A2, and BSP-A3. These proteins contain two homologous domains that are similar to type II structures present in the gelatin-binding domain of fibronectin. The present data have revealed that these proteins, like fibronectin, also form complexes with gelatin, a denatured collagen. Based on this property, a single step affinity purification method has been developed. In addition to these three proteins BSP-A1, −A2 and −A3, another protein with an apparent molecular weight of 30,000 dalton (named BSP-30-kDa) also bound to the gelatin-agarose column. Elution of these proteins from affinity columns using a linear gradient of either urea or arginine gave essentially the same pattern with a high yield of 90–95%. The purified proteins were homogeneous by SDS-polyacrylamide gel electrophoresis, amino acid composition and HPLC. Chromatography of bull seminal vesicular fluid also exhibited an elution pattern similar to that obtained for bull seminal plasma. The availability of these purified proteins should aid in understanding the physiology of these gelatin-binding proteins.

scholarly journals A hag Mutant of Moraxella catarrhalis Strain O35E Is Deficient in Hemagglutination, Autoagglutination, and Immunoglobulin D-Binding Activities

2002 ◽  
Vol 70 (8) ◽  
pp. 4523-4533 ◽  
Author(s):  
Melanie M. Pearson ◽  
Eric R. Lafontaine ◽  
Nikki J. Wagner ◽  
Joseph W. St. Geme ◽  
Eric J. Hansen
Keyword(s):  
Moraxella Catarrhalis ◽  
Insertional Mutagenesis ◽  
Human Erythrocytes ◽  
Nucleotide Sequence Analysis ◽  
Dense Layer ◽  
Wild Type ◽  
Triple Mutant ◽  
Gene Encoding ◽  
Transmission Electron ◽  
Immunoglobulin D

ABSTRACT Previous studies correlated the presence of a 200-kDa protein on the surface of Moraxella catarrhalis with the ability of this organism to agglutinate human erythrocytes (M. Fitzgerald, R. Mulcahy, S. Murphy, C. Keane, D. Coakley, and T. Scott, FEMS Immunol. Med. Microbiol. 18:209-216, 1997). In the present study, the gene encoding the 200-kDa protein (designated Hag) of M. catarrhalis strain O35E was subjected to nucleotide sequence analysis and then was inactivated by insertional mutagenesis. The isogenic hag mutant was unable to agglutinate human erythrocytes and lost its ability to autoagglutinate but was still attached at wild-type levels to several human epithelial cell lines. The hag mutation also eliminated the ability of this mutant strain to bind human immunoglobulin D. The presence of the Hag protein on the M. catarrhalis cell surface, as well as that of the UspA1 and UspA2 proteins (C. Aebi, I. Maciver, J. L. Latimer, L. D. Cope, M. K. Stevens, S. E. Thomas, G. H. McCracken, Jr., and E. J. Hansen, Infect. Immun. 65:4367-4377, 1997), was investigated by transmission electron and cryoimmunoelectron microscopy. Wild-type M. catarrhalis strain O35E possessed a dense layer of surface projections, whereas an isogenic uspA1 uspA2 hag triple mutant version of this strain did not possess any detectable surface projections. Examination of a uspA1 uspA2 double mutant that expressed the Hag protein revealed the presence of a relatively sparse layer of surface projections, similar to those seen on a uspA2 hag mutant that expressed UspA1. In contrast, a uspA1 hag mutant that expressed UspA2 formed a very dense layer of relatively short surface projections. These results indicate that the surface-exposed Hag protein and UspA1 and UspA2 have the potential to interact both with each other and directly with host defense systems.

Isolation of Human Fibrinogen and its Derivatives by Affinity Chromatography on Gly-Pro-Arg-Pro-Lys-Fractogel

1990 ◽  
Vol 63 (03) ◽  
pp. 439-444 ◽  
Author(s):  
C Kuyas ◽  
A Haeberli ◽  
P Walder ◽  
P W Straub
Keyword(s):  
Gel Electrophoresis ◽  
Affinity Purification ◽  
Polyacrylamide Gel Electrophoresis ◽  
Ease Of Use ◽  
Terminal Sequence ◽  
Purification Method ◽  
Human Fibrinogen ◽  
Isolation Methods ◽  
One Step ◽  
Complementary Binding

SummaryWith an immobilized synthetic pentapeptide GlyProArgProLys comprising the N-terminal sequence GlyProArg of the α-chain of fibrin, a new affinity method for the quantitative isolation of fibrinogen out of anticoagulated plasma was developed. The method proved to be superior to all known isolation methods in respect to ease of use and yield, since fibrinogen could be isolated in one step out of plasma with a recovery of more than 95% when compared to the immunologically measurable amounts of fibrinogen. Moreover the amounts of contaminating proteins such as fibronectin, factor XIII or plasminogen were negligible and the purity of the isolated fibrinogen was higher than 95% as measured by polyacrylamide gel electrophoresis. The clottability was 90% and more. Another advantage of this affinity purification method is the possibility to isolate fibrinogen quantitatively out of small plasma samples (<5 ml). Further, abnormal fibrinogen molecules, provided their complementary binding site for GlyProArg is preserved, may also be quantitatively isolated independent of any solubility differences as compared to normal fibrinogen. In addition fibrin(ogcn) fragments originating from plasmic digestion can be separated on the basis of their affinity to GlyProArg. The described affinity gel can be used more than 50 times without any loss of capacity.

Flexible k-mers with variable-length indels for identifying binding sequences of protein dimers

2019 ◽  
Vol 21 (5) ◽  
pp. 1787-1797
Author(s):  
Chenyang Hong ◽  
Kevin Y Yip
Keyword(s):  
Binding Proteins ◽  
Affinity Purification ◽  
Classification Performance ◽  
Variable Regions ◽  
Binding Motifs ◽  
New Class ◽  
Protein Dimers ◽  
Sequence Patterns ◽  
Standard Chip ◽  
Exponential Enrichment

Abstract Many DNA-binding proteins interact with partner proteins. Recently, based on the high-throughput consecutive affinity-purification systematic evolution of ligands by exponential enrichment (CAP-SELEX) method, many such protein pairs have been found to bind DNA with flexible spacing between their individual binding motifs. Most existing motif representations were not designed to capture such flexibly spaced regions. In order to computationally discover more co-binding events without prior knowledge about the identities of the co-binding proteins, a new representation is needed. We propose a new class of sequence patterns that flexibly model such variable regions and corresponding algorithms that identify co-bound sequences using these patterns. Based on both simulated and CAP-SELEX data, features derived from our sequence patterns lead to better classification performance than patterns that do not explicitly model the variable regions. We also show that even for standard ChIP-seq data, this new class of sequence patterns can help discover co-bound events in a subset of sequences in an unsupervised manner. The open-source software is available at https://github.com/kevingroup/glk-SVM.

scholarly journals The surface (S)-layer gene cspB of Corynebacterium glutamicum is transcriptionally activated by a LuxR-type regulator and located on a 6 kb genomic island absent from the type strain ATCC 13032

Microbiology ◽  
2006 ◽  
Vol 152 (4) ◽  
pp. 923-935 ◽  
Author(s):  
Nicole Hansmeier ◽  
Andreas Albersmeier ◽  
Andreas Tauch ◽  
Thomas Damberg ◽  
Robert Ros ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Affinity Purification ◽  
Regulatory Protein ◽  
Direct Repeat ◽  
Peptide Mass Fingerprinting ◽  
Gene Encoding ◽  
Force Microscopy ◽  
Flight Mass Spectrometry ◽  
Peptide Mass ◽  
Rapid Amplification

The surface (S)-layer gene region of the Gram-positive bacterium Corynebacterium glutamicum ATCC 14067 was identified on fosmid clones, sequenced and compared with the genome sequence of C. glutamicum ATCC 13032, whose cell surface is devoid of an ordered S-layer lattice. A 5·97 kb DNA region that is absent from the C. glutamicum ATCC 13032 chromosome was identified. This region includes cspB, the structural gene encoding the S-layer protomer PS2, and six additional coding sequences. PCR experiments demonstrated that the respective DNA region is conserved in different C. glutamicum wild-type strains capable of S-layer formation. The DNA region is flanked by a 7 bp direct repeat, suggesting that illegitimate recombination might be responsible for gene loss in C. glutamicum ATCC 13032. Transfer of the cloned cspB gene restored the PS2− phenotype of C. glutamicum ATCC 13032, as confirmed by visualization of the PS2 proteins by SDS-PAGE and imaging of ordered hexagonal S-layer lattices on living C. glutamicum cells by atomic force microscopy. Furthermore, the promoter of the cspB gene was mapped by 5′ rapid amplification of cDNA ends PCR and the corresponding DNA fragment was used in DNA affinity purification assays. A 30 kDa protein specifically binding to the promoter region of the cspB gene was purified. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry and peptide mass fingerprinting of the purified protein led to the identification of the putative transcriptional regulator Cg2831, belonging to the LuxR regulatory protein family. Disruption of the cg2831 gene in C. glutamicum resulted in an almost complete loss of PS2 synthesis. These results suggested that Cg2831 is a transcriptional activator of cspB gene expression in C. glutamicum.

Nonencapsulated or nontypeableHaemophilus influenzaeare more likely than their encapsulated or serotypeable counterparts to have mutations in their fucose operon

2011 ◽  
Vol 57 (12) ◽  
pp. 982-986 ◽  
Author(s):  
Michelle L. Shuel ◽  
Kathleen E. Karlowsky ◽  
Dennis K.S. Law ◽  
Raymond S.W. Tsang
Keyword(s):  
Nucleotide Sequence ◽  
Haemophilus Influenzae ◽  
Dna Sequencing ◽  
Multilocus Sequence Typing ◽  
Population Biology ◽  
Housekeeping Genes ◽  
Sequence Variations ◽  
Sequence Types ◽  
Complete Deletion

Population biology of Haemophilus influenzae can be studied by multilocus sequence typing (MLST), and isolates are assigned sequence types (STs) based on nucleotide sequence variations in seven housekeeping genes, including fucK. However, the ST cannot be assigned if one of the housekeeping genes is absent or cannot be detected by the current protocol. Occasionally, strains of H. influenzae have been reported to lack the fucK gene. In this study, we examined the prevalence of this mutation among our collection of H. influenzae isolates. Of the 704 isolates studied, including 282 encapsulated and 422 nonencapsulated isolates, nine were not typeable by MLST owing to failure to detect the fucK gene. All nine fucK-negative isolates were nonencapsulated and belonged to various biotypes. DNA sequencing of the fucose operon region confirmed complete deletion of genes in the operon in seven of the nine isolates, while in the remaining two isolates, some of the genes were found intact or in parts. The significance of these findings is discussed.

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