scholarly journals Heterogeneity of human serum amyloid A proteins.

1980 ◽  
Vol 152 (3) ◽  
pp. 641-656 ◽  
Author(s):  
L L Bausserman ◽  
P N Herbert ◽  
K P McAdam
Keyword(s):  
Amino Acid ◽  
Serum Amyloid A ◽  
Polyacrylamide Gel ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Systemic Lupus Erythematosis ◽  
Secondary Amyloidosis ◽  
Single Chain ◽  
Amino Acid Compositions ◽  
Amyloid A

Serum amyloid A proteins (SAA), presumed precursors of the tissue amyloid A proteins (AA) characteristic of secondary amyloidosis, have been isolated from the plasma high-density lipoproteins (HDL) of normals after etiocholanolone-induced inflammation and from patients with Wegener's granulomatosis, systemic lupus erythematosis, juvenile rheumatoid arthritis, Waldenström's macroglobulinemia, and Goodpasture's syndrome. At least six polymorphic forms of SAA wer identified among the low molecular weight proteins of HDL, and these comprosed up to 27% of the total HDL protein. Gel and ion-exchange chromatography permitted isolation of the SAA polymorphs in homogeneous form. Their amino acid compositions were very similar, they were indistinguishable in cationic and sodium dodecyl sulfate-polyacrylamide gel electrophoresis systems, and each had the terminal sequency COOH-Tyr-Lys-Phe-. Charge heterogeneity in anionic-urea polyacrylamide gel electropherograms was unaffected by neuaminidase treatment, and none of the SAA protein bands stained with the periodate-Schiff reagent. The two major SAA polymorphs, designated SAA4 and SAA5 according to their order of elution from DEAE-cellulose, had different NH2-terminal sequences. Manual Edman degradation demonstrated NH2-arg-ser-phe-phe- for SAA4 and NH2-ser-phe-phe- for SAA5. This NH2-terminal heterogeneity corresponds to that most frequently reported for AA and suggests that microheterogeneity in SAA may underlie that already documented in AA. Sufficient quantitites of the other SAA polymorphs were not available for similar analyses, but the amino acid compositions do not indicate that NH2-terminal heterogeneity accounts for all of the observed polymorphism. Artifactual polymorphism also appears unlikely, and the heterogeneiy of SAA may reflect origin from more than one cell type with or without posttranslational modificaton. We calculate from quantitative COOH-terminal analyses that SAA is of 11,000-11,900 mol wt. Primary structure studies have shown AA t be a single chain protein of 76 residues, and SAA, therefore, appears to contain a peptide of 33 amino acids that is missing from AA.

scholarly journals Adenoviral expression of murine serum amyloid A proteins to study amyloid fibrillogenesis

1998 ◽  
Vol 332 (3) ◽  
pp. 721-728 ◽  
Author(s):  
Mark S. KINDY ◽  
Amy R. KING ◽  
Jin YU ◽  
Connie GERARDOT ◽  
Joel WHITLEY ◽  
...  
Keyword(s):  
Acute Phase ◽  
Half Life ◽  
Serum Amyloid A ◽  
Amyloid Fibrils ◽  
Serum Amyloid ◽  
Vector System ◽  
High Density Lipoproteins ◽  
Secondary Amyloidosis ◽  
Amyloid A ◽  
J Protein

Serum amyloid A (SAA) proteins are one of the most inducible acute-phase reactants and are precursors of secondary amyloidosis. In the mouse, SAA1 and SAA2 are induced in approximately equal quantities in response to amyloid induction models. These two isotypes differ in only 9 of 103 amino acid residues; however, only SAA2 is selectively deposited into amyloid fibrils. SAA expression in the CE/J mouse species is an exception in that gene duplication did not occur and the CE/J variant is a hybrid molecule sharing features of SAA1 and SAA2. However, even though it is more closely related to SAA2 it is not deposited as amyloid fibrils. We have developed an adenoviral vector system to overexpress SAA proteins in cell culture to determine the ability of these proteins to form amyloid fibrils, and to study the structural features in relation to amyloid formation. Both the SAA2 and CE/J SAA proteins were synthesized in large quantities and purified to homogeneity. Electron microscopic analysis of the SAA proteins revealed that the SAA2 protein was capable of forming amyloid fibrils, whereas the CE/J SAA was incapable. Radiolabelled SAAs were associated with normal or acute-phase high-density lipoproteins (HDLs); we examined them for their clearance from the circulation. In normal mice, SAA2 had a half-life of 70 min and CE/J SAA had a half-life of 120 min; however, in amyloid mice 50% of the SAA2 cleared in 55 min, compared with 135 min for the CE/J protein. When the SAA proteins were associated with acute-phase HDLs, SAA2 clearance was decreased to 60 min in normal mice compared with 30 min in amyloidogenic mice. Both normal and acute-phase HDLs were capable of depositing SAA2 into preformed amyloid fibrils, whereas the CE/J protein did not become associated with amyloid fibrils. This established approach opens the doors for large-scale SAA production and for the examination of specific amino acids involved in the fibrillogenic capability of the SAA2 molecule in vitro and in vivo.

scholarly journals Serum amyloid A is a chemoattractant: induction of migration, adhesion, and tissue infiltration of monocytes and polymorphonuclear leukocytes.

1994 ◽  
Vol 180 (1) ◽  
pp. 203-209 ◽  
Author(s):  
R Badolato ◽  
J M Wang ◽  
W J Murphy ◽  
A R Lloyd ◽  
D F Michiel ◽  
...  
Keyword(s):  
Acute Phase ◽  
Polymorphonuclear Leukocytes ◽  
Serum Amyloid A ◽  
High Density ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Secondary Amyloidosis ◽  
Polymorphonuclear Cells ◽  
Amyloid A ◽  
Cell Adhesion Molecule 1

Serum amyloid A (SAA) is an acute phase protein that in the blood is bound to high density lipoproteins; SAA is secreted mainly by hepatocytes, and its concentration increases in the blood up to 1000 times during an inflammatory response. At present, its biological function is unclear. Since some forms of secondary amyloidosis are caused by deposition in tissues of peptides derived from the SAA and leukocytes seem to be involved in this process, we investigated the effect of human SAA on human monocytes and polymorphonuclear cells (PMN). When recombinant human SAA (rSAA) was used at concentrations corresponding to those found during the acute phase (> 0.8 microM), it induced directional migration of monocytes and polymorphonuclear leukocytes. Preincubation of rSAA with high density lipoproteins blocked this chemoattractant activity for both monocytes and PMN. rSAA also regulated the expression of the adhesion proteins CD11b and leukocyte cell adhesion molecule 1 and induced the adhesion of PMN and monocytes to umbilical cord vein endothelial cell monolayers. When subcutaneously injected into mice, rSAA recruited PMN and monocytes at the injection site. On the basis of these data, we suggest that SAA may participate in enhancing the migration of monocytes and PMN to inflamed tissues during an acute phase response.

scholarly journals Aggregation of Mouse Serum Amyloid A Protein Was Promoted by Amyloid-Enhancing Factors with the More Genetically Homologous Serum Amyloid A

2021 ◽  
Vol 22 (3) ◽  
pp. 1036
Author(s):  
Xuguang Lin ◽  
Kenichi Watanabe ◽  
Masahiro Kuragano ◽  
Kiyotaka Tokuraku
Keyword(s):  
Amino Acid ◽  
Serum Amyloid A ◽  
Animal Species ◽  
Amino Acid Sequences ◽  
Serum Amyloid ◽  
Mouse Serum ◽  
Aa Amyloidosis ◽  
Basic Residue ◽  
Amyloid A ◽  
Serum Amyloid A Protein

Amyloid A (AA) amyloidosis is a condition in which amyloid fibrils characterized by a linear morphology and a cross-β structure accumulate and are deposited extracellularly in organs, resulting in chronic inflammatory diseases and infections. The incidence of AA amyloidosis is high in humans and several animal species. Serum amyloid A (SAA) is one of the most important precursor amyloid proteins and plays a vital step in AA amyloidosis. Amyloid enhancing factor (AEF) serves as a seed for fibril formation and shortens the onset of AA amyloidosis sharply. In this study, we examined whether AEFs extracted and purified from five animal species (camel, cat, cattle, goat, and mouse) could promote mouse SAA (mSAA) protein aggregation in vitro using quantum-dot (QD) nanoprobes to visualize the aggregation. The results showed that AEFs shortened and promoted mSAA aggregation. In addition, mouse and cat AEFs showed higher mSAA aggregation-promoting activity than the camel, cattle, and goat AEFs. Interestingly, homology analysis of SAA in these five animal species revealed a more similar amino acid sequence homology between mouse and cat than between other animal species. Furthermore, a detailed comparison of amino acid sequences suggested that it was important to mSAA aggregation-promoting activity that the 48th amino acid was a basic residue (Lys) and the 125th amino acid was an acidic residue (Asp or Glu). These data imply that AA amyloidosis exhibits higher transmission activity among animals carrying genetically homologous SAA gene, and may provide a new understanding of the pathogenesis of amyloidosis.

scholarly journals Serum amyloid A forms stable oligomers that disrupt vesicles at lysosomal pH and contribute to the pathogenesis of reactive amyloidosis

2017 ◽  
Vol 114 (32) ◽  
pp. E6507-E6515 ◽  
Author(s):  
Shobini Jayaraman ◽  
Donald L. Gantz ◽  
Christian Haupt ◽  
Olga Gursky
Keyword(s):  
Serum Amyloid A ◽  
Major Complication ◽  
Lipid Vesicles ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Aa Amyloidosis ◽  
Intrinsically Disordered ◽  
Amyloid A ◽  
Α Helix ◽  
Structural Methods

Serum amyloid A (SAA) is an acute-phase plasma protein that functions in innate immunity and lipid homeostasis. SAA is a protein precursor of reactive AA amyloidosis, the major complication of chronic inflammation and one of the most common human systemic amyloid diseases worldwide. Most circulating SAA is protected from proteolysis and misfolding by binding to plasma high-density lipoproteins. However, unbound soluble SAA is intrinsically disordered and is either rapidly degraded or forms amyloid in a lysosome-initiated process. Although acidic pH promotes amyloid fibril formation by this and many other proteins, the molecular underpinnings are unclear. We used an array of spectroscopic, biochemical, and structural methods to uncover that at pH 3.5–4.5, murine SAA1 forms stable soluble oligomers that are maximally folded at pH 4.3 with ∼35% α-helix and are unusually resistant to proteolysis. In solution, these oligomers neither readily convert into mature fibrils nor bind lipid surfaces via their amphipathic α-helices in a manner typical of apolipoproteins. Rather, these oligomers undergo an α-helix to β-sheet conversion catalyzed by lipid vesicles and disrupt these vesicles, suggesting a membranolytic potential. Our results provide an explanation for the lysosomal origin of AA amyloidosis. They suggest that high structural stability and resistance to proteolysis of SAA oligomers at pH 3.5–4.5 help them escape lysosomal degradation, promote SAA accumulation in lysosomes, and ultimately damage cellular membranes and liberate intracellular amyloid. We posit that these soluble prefibrillar oligomers provide a missing link in our understanding of the development of AA amyloidosis.

scholarly journals Amyloid deposition in granuloma of tuberculosis patients: A pilot study

2021 ◽  
Author(s):  
Shreya Ghosh ◽  
Akansha Garg ◽  
Chayanika Kala ◽  
Ashwani Kumar Thakur
Keyword(s):  
Serum Amyloid A ◽  
Amyloid Deposition ◽  
Serum Amyloid ◽  
Secondary Amyloidosis ◽  
Amyloid Formation ◽  
Tuberculosis Patients ◽  
Amyloid A ◽  
Inflammatory Conditions ◽  
Amyloid Deposits ◽  
Serum Amyloid A Protein

AbstractThe formation of granuloma is one of the characteristic feature of tuberculosis. Besides, rise in the concentration of acute phase response proteins mainly serum amyloid A is the indicator for chronic inflammation associated with tuberculosis. Serum amyloid A drives secondary amyloidosis in tuberculosis and other chronic inflammatory conditions. The linkage between serum amyloid A (SAA) protein and amyloid deposition site is not well understood in tuberculosis and other chronic inflammatory conditions. We hypothesized that granuloma could be a potential site for amyloid deposition because of the presence of serum amyloid A protein and proteases that cleave SAA and trigger amyloid formation. Based on this hypothesis, for the first time we have shown the presence of amyloid deposits in the granuloma of tuberculosis patients using the gold standard, Congo red dye staining.

Serum amyloid A and high density lipoproteins during the acute phase response

1988 ◽  
Vol 18 (6) ◽  
pp. 619-626 ◽  
Author(s):  
LINDA L. BAUSSERMAN ◽  
D. N. BERNIER ◽  
K. P. W. J. McADAM ◽  
P. N. HERBERT
Keyword(s):  
Acute Phase ◽  
Acute Phase Response ◽  
Serum Amyloid A ◽  
High Density ◽  
Phase Response ◽  
Serum Amyloid ◽  
High Density Lipoproteins ◽  
Amyloid A

scholarly journals Identification of Levels of Serum Amyloid A and Apolipoprotein A1 in Serum Proteomic Analysis of Neuropsychiatric Systemic Lupus Erythematosus Patients

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Nancy P. Duarte-Delgado ◽  
Tania P. Lujan ◽  
Álvaro Arbeláez-Cortés ◽  
Jenny García-Valencia ◽  
Adriana Zapata ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Serum Amyloid A ◽  
Serum Amyloid ◽  
Apolipoprotein A1 ◽  
High Density Lipoproteins ◽  
Systemic Lupus ◽  
Altered Level ◽  
Amyloid A ◽  
Neuropsychiatric Systemic Lupus Erythematosus

Neuropsychiatric Systemic Lupus Erythematosus (NPSLE) has multiple pathogenic mechanisms that cause diverse manifestations and whose diagnosis is challenging because of the absence of appropriate diagnostic tests. In the present study the application of proteomics using two-dimensional electrophoresis (2D) and mass spectrometry (MS) allowed the comparison of the protein profile of the serum low and high abundance protein fractions of NPSLE patients (NPSLE group) and SLE without neuropsychiatric syndromes (SLE group), Neuropsychiatric syndromes not associated with SLE (NPnoSLE groups), and healthy controls (CTRL group). The gels obtained were digitalized and analyzed with the PDQuest software. The statistical analysis of the spots was performed using the nonparametric Kruskal Wallis and Dunn's multiple comparison tests. Two spots showed significant differences and were identified by MS. Spot 4009 was significantly lower in NPSLE with regard to NPnoSLE (p= 0,004) and was identified as apolipoprotein A1 (APOA1) (score 809-1132). Spot 8001 was significantly higher in NPSLE regarding CTRL and NPnoSLE (p= 0,01 y 0,03, respectively) and was identified as serum amyloid A (SAA) (score 725-2488). The proinflammatory high density lipoproteins (HDL) have been described in SLE. In this HDL the decrease of APOA1 is followed by an increase in SAA. This altered level of both proteins may be related to the inflammatory state that is characteristic of an autoimmune disease like SLE, but this is not specific for NPSLE.

The Revised Amino Acid Sequence of Serum Amyloid A (SAA) Protein in Mink

1993 ◽  
Vol 37 (6) ◽  
pp. 696-697 ◽  
Author(s):  
P. V. SYVERSEN ◽  
K. SLETTEN ◽  
G. MARHAUG ◽  
G. HUSBY ◽  
B. LIUM
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Serum Amyloid A ◽  
Serum Amyloid ◽  
Amyloid A

Effect of amino acid variations in the central region of human serum amyloid A on the amyloidogenic properties

2014 ◽  
Vol 444 (1) ◽  
pp. 92-97 ◽  
Author(s):  
Hiroka Takase ◽  
Masafumi Tanaka ◽  
Sachiko Miyagawa ◽  
Toshiyuki Yamada ◽  
Takahiro Mukai
Keyword(s):  
Amino Acid ◽  
Human Serum ◽  
Central Region ◽  
Serum Amyloid A ◽  
Serum Amyloid ◽  
Amyloid A
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