THE C3-ACTIVATOR SYSTEM: AN ALTERNATE PATHWAY OF COMPLEMENT ACTIVATION

1971 ◽  
Vol 134 (3) ◽  
pp. 90-108 ◽  
Author(s):  
Otto Götze ◽  
Hans J. Müller-Eberhard
Keyword(s):  
Molecular Weight ◽  
Complement Activation ◽  
Activation Mechanism ◽  
E Coli ◽  
Clinical Observations ◽  
Naturally Occurring ◽  
Acidic Peptide ◽  
Relationship Of ◽  
The Relationship ◽  
Activator System

Evidence has accumulated indicating the existence of a second complement activation mechanism which is functionally analogous to C1, C2, and C4. The noncomplement protein C3PA, previously recognized through its ability to form a complex enzyme with a protein from cobra venom, appears to be the precursor of the C4,2 analogue. It is a thermolabile ß-globulin with a molecular weight of 80,000. When serum is treated with naturally occurring plant or bacterial polysaccharides, the C3PA is cleaved into at least two fragments, one having the electrophoretic mobility of a γ-globulin and a molecular weight of 60,000, and the other being an acidic peptide with a molecular weight of 20,000. The larger fragment has the ability to cleave C3 into C3a and C3b and is therefore called C3 activator. It arises from the action of an as yet unidentified serum enzyme upon the C3PA, which is tentatively called C3PA convertase. In addition to endotoxins, yeast cell walls, inulin, and agar, aggregates of immunoglobulins were found to be activating substances, including human IgA, guinea pig γ1, and duck antibody. Serum depleted of C3PA had reduced E. coli bactericidal and increased hemolytic activity. The relationship of the C3-activator system to experimental and clinical observations has been discussed.

scholarly journals Exploring the taxonomical and functional profile of As Burgas hot spring focusing on thermostable β-galactosidases

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
María-Eugenia DeCastro ◽  
Michael P. Doane ◽  
Elizabeth Ann Dinsdale ◽  
Esther Rodríguez-Belmonte ◽  
María-Isabel González-Siso
Keyword(s):  
Microbial Community ◽  
Hot Spring ◽  
Functional Characterization ◽  
Tca Cycle ◽  
Maximal Activity ◽  
Sulfur Cycle ◽  
E Coli ◽  
Complex Microbial Community ◽  
Relationship Of ◽  
The Relationship

AbstractIn the present study we investigate the microbial community inhabiting As Burgas geothermal spring, located in Ourense (Galicia, Spain). The approximately 23 Gbp of Illumina sequences generated for each replicate revealed a complex microbial community dominated by Bacteria in which Proteobacteria and Aquificae were the two prevalent phyla. An association between the two most prevalent genera, Thermus and Hydrogenobacter, was suggested by the relationship of their metabolism. The high relative abundance of sequences involved in the Calvin–Benson cycle and the reductive TCA cycle unveils the dominance of an autotrophic population. Important pathways from the nitrogen and sulfur cycle are potentially taking place in As Burgas hot spring. In the assembled reads, two complete ORFs matching GH2 beta-galactosidases were found. To assess their functional characterization, the two ORFs were cloned and overexpressed in E. coli. The pTsbg enzyme had activity towards o-Nitrophenyl-β-d-galactopyranoside (ONPG) and p-Nitrophenyl-β-d-fucopyranoside, with high thermal stability and showing maximal activity at 85 °C and pH 6, nevertheless the enzyme failed to hydrolyze lactose. The other enzyme, Tsbg, was unable to hydrolyze even ONPG or lactose. This finding highlights the challenge of finding novel active enzymes based only on their sequence.

scholarly journals Characterization of the β-lactamase specified by the resistance factor R-1818 in Escherichia coli K12 and other Gram-negative bacteria

1971 ◽  
Vol 123 (4) ◽  
pp. 501-505 ◽  
Author(s):  
J. W. Dale
Keyword(s):  
Escherichia Coli ◽  
Host Species ◽  
Host Bacterium ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
R Factor ◽  
Relationship Of ◽  
The Relationship

1. The amino acid composition of the β-lactamase from E. coli (R-1818) was determined. 2. The R-1818 β-lactamase is inhibited by formaldehyde, hydroxylamine, sodium azide, iodoacetamide, iodine and sodium chloride. 3. The Km values for benzylpenicillin, ampicillin and oxacillin have been determined by using the R-factor enzyme from different host species. The same values were obtained, irrespective of the host bacterium. 4. The molecular weight of the enzyme was found to be 44600, and was the same for all host species. 5. The relationship of R-1818 and R-GN238 β-lactamases is discussed.

scholarly journals Myeloperoxidase Selectively Binds and Selectively Kills Microbes

2010 ◽  
Vol 79 (1) ◽  
pp. 474-485 ◽  
Author(s):  
Robert C. Allen ◽  
Jackson T. Stephens
Keyword(s):  
Streptococcus Pyogenes ◽  
Direct Evidence ◽  
Minimal Bactericidal Concentration ◽  
Viridans Streptococci ◽  
E Coli ◽  
Horse Blood ◽  
Valid Comparison ◽  
Relationship Of ◽  
The Relationship ◽  
Lysed Horse Blood

ABSTRACTMyeloperoxidase (MPO) is reported to selectively bind to bacteria. The present study provides direct evidence of MPO binding selectivity and tests the relationship of selective binding to selective killing. The microbicidal effectiveness of H2O2and of OCl−was compared to that of MPO plus H2O2. Synergistic microbicidal action was investigated by combiningStreptococcus sanguinis, a H2O2-producing microbe showing low MPO binding, with high-MPO-bindingEscherichia coli,Staphylococcus aureus, orPseudomonas aeruginosawithout exogenous H2O2, with and without MPO, and with and without erythrocytes (red blood cells [RBCs]). Selectivity of MPO microbicidal action was conventionally measured as the MPO MIC and minimal bactericidal concentration (MBC) for 82 bacteria includingE. coli,P. aeruginosa,S. aureus,Enterococcus faecalis,Streptococcus pyogenes,Streptococcus agalactiae, and viridans streptococci. Both H2O2and OCl−destroyed RBCs at submicrobicidal concentrations. Nanomolar concentrations of MPO increased H2O2microbicidal action 1,000-fold. Streptococci plus MPO produced potent synergistic microbicidal action against all microbes tested, and RBCs caused only a small decrease in potency without erythrocyte damage. MPO directly killed H2O2-producingS. pyogenesbut was ineffective against non-H2O2-producingE. faecalis. The MPO MICs and MBCs forE. coli,P. aeruginosa, andS. aureuswere significantly lower than those forE. faecalis.The streptococcal studies showed much higher MIC/MBC results, but such testing required lysed horse blood-supplemented medium, thus preventing valid comparison of these results to those for the other microbes.E. faecalisMPO binding is reportedly weak compared to binding ofE. coli,P. aeruginosa, andS. aureusbut strong compared to binding of streptococci. Selective MPO binding results in selective killing.

The Relationship of Narcissism with Workaholism, Work Engagement, and Professional Position

2012 ◽  
Vol 40 (6) ◽  
pp. 881-890 ◽  
Author(s):  
Cecilie Schou Andreassen ◽  
Holger Ursin ◽  
Hege R. Eriksen ◽  
Ståle Pallesen
Keyword(s):  
Work Engagement ◽  
Regression Analyses ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Work Enjoyment ◽  
Clinical Observations ◽  
Narcissistic Personality Inventory ◽  
Bank Employees ◽  
Relationship Of ◽  
The Relationship

We examined scores on the Narcissistic Personality Inventory (NPI; Raskin & Terry, 1988) in relation to drive to work, enjoyment of and engagement in work, and professional position. A sample of 235 Norwegian bank employees completed a cross-sectional survey. We found that managers scored higher than subordinates on all measures. NPI scores correlated significantly and positively with drive, enjoyment of and engagement in work. Multiple regression analyses controlling for demographic and work variables showed that narcissism was significantly related to enjoyment of work and work engagement but unrelated to drive. Although the associations were rather weak, our findings support previous clinical observations of narcissistic traits in workaholics as well as findings in empirical research on narcissistic traits in managers.

scholarly journals A comparison of the levels of faecal indicator bacteria in water and human faeces in a rural area of a tropical developing country (Sierra Leone)

1982 ◽  
Vol 89 (1) ◽  
pp. 69-78 ◽  
Author(s):  
R. C. Wright
Keyword(s):  
Sierra Leone ◽  
Water Sources ◽  
Indicator Bacteria ◽  
Rural Settlements ◽  
Faecal Coliforms ◽  
Human Faeces ◽  
E Coli ◽  
Faecal Samples ◽  
Relationship Of ◽  
The Relationship

SUMMARYThe levels of faecal coliforms (FC), indole-positive FC (presumptiveEscherichia coli), faecal streptococci (FS),Streptococcus faecalisandClostridium perfringensin the natural water sources used by 29 rural settlements in Sierra Leone were investigated. Levels of the same indicators in human faeces were also investigated. The incidence ofSalmonellaspp. in both habitats and the temperature, pH and conductivity of water sources were also recorded. All water sources were contaminated with the indicator bacteria, mean numbers of which occurred in the relationship FC > presumptiveE. coli≏ FS ≏C. perfringens>S. faecalis.FC were also predominant in human faeces, the relationship of means being FC ≏ presumptiveE. coli> FS >S. faecalis>C. perfringens.The need for confirmation of FC counts obtained from water sources was indicated by the large number of positive tubes produced in the FC multiple-tube dilution test from some samples which could not be confirmed as presumptiveE. coli. Salmonellaspp. were isolated from 13 water sources and 6% of faecal samples. Mean water temperature was high (26·2 °C), pH low (5·04) and conductivity low (34μS cm−1). PresumptiveE. coliwas considered the most appropriate indicator of faecal pollution of the types of water investigated.

scholarly journals Molecular Simulation of Hyperbranched Polyester

2009 ◽  
Vol 5 (1) ◽  
pp. 563-569
Author(s):  
Liu Yanmei ◽  
Li Haihua ◽  
Tai Yulei ◽  
Chao Guoku ◽  
Zhao Yajuan
Keyword(s):  
Molecular Weight ◽  
Simulation Model ◽  
Empirical Equation ◽  
Gel Permeation Chromatography ◽  
Acid Value ◽  
Hyperbranched Polyester ◽  
Molecular Weights ◽  
The Core ◽  
Relationship Of ◽  
The Relationship

A new types of hyperbranched polyester was synthesized by the 2,2-bis(hydroxymethyl) propionic acid as an AB2-type monomer and glycerol as the core moiety. Molecular weights were confirmed by Gel Permeation Chromatography. Acid values were titrated by KOH. The hydroxy value was obtained by titration. Furthermore, we calculate logarithmic value of acid value, hydroxy value, and molecular weight, respectively, and the simulation model curves were obtained. Based on the simulation model curves, we establish the empirical equation of the relationship of molecular weight, acid value and hydroxy value.

scholarly journals Relationship of contact activation cofactor (CAC) procoagulant activity to kininogen

Blood ◽  
1977 ◽  
Vol 49 (6) ◽  
pp. 935-945 ◽  
Author(s):  
S Schiffman ◽  
P Lee ◽  
DI Feinstein ◽  
R Pecci
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Procoagulant Activity ◽  
Antigenic Determinants ◽  
High Molecular Weight Kininogen ◽  
Contact Activation ◽  
Precipitin Line ◽  
A Site ◽  
Relationship Of ◽  
The Relationship

Abstract Contact activation cofactor (CAC) facilitates the interaction of factors XI and XII. Patients lacking CAC have a coagulation defect and are deficient in high molecular weight kininogen. The coincidence of these two defects suggests that a single protein may be responsible for both physiologic functions. Immunologic and activity studies have been made on isolated CAC to clarify the relationship between CAC and kininogen. CAC forms a single precipitin line with anti-human kininogen, and antikininogen neutralizes CAC activity. CAC and high molecular weight kininogen show a reaction of identity on immunodiffusion against rabbit anti-CAC. Anti-CAC forms two precipitin lines with normal plasma which can be identified as high and low molecular weight kininogen. Monospecific immunoabsorbed anti-CAC forms a single precipitin line with plasma high molecular weight kininogen and neutralizes CAC activity. Cleavage of kinin fragment from CAC by insoluble trypsin or kalikrein does not proportionally reduce procoagulant activity. CAC neutralized by anti-CAC can release kinins on exposure to trypsin or kallikrein. The results support the conclusions that CAC procoagulant activity is a function of high molecular weight kininogen, that antigenic determinants unique to high molecular weight kininogen are shared by the CAC portion of the molecule, and that the clotting reactions may occur at a site removed from the kinin peptide.

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