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M A Alim

Publications and source records attributed to M A Alim.

6 recordsLinked to original sources

Fluoride exposure inhibits protein expression and enzyme activity in the lung-stage larvae of Ascaris suum.

Sodium fluoride (NaF) is an anion that has been previously shown to block the moulting process of Ascaris suum larvae. This study describes moulting and development-specific protein expression profiles of A. suum lung-stage L3 (AsLL3) following NaF exposure. AsLL3s cultured in the presence or absence of NaF were prepared for protein analysis using two-dimensional (2D) electrophoresis. NaF exposure inhibited at least 22 proteins in AsLL3 compared with moulted larvae (i.e. AsLL4). A further comparison of AsLL4 with those of pre-cultured AsLL3 and NaF-exposed AsLL3 revealed 8 stage-specifically and 4 over-expressed proteins. Immunoblot analysis revealed an inhibition by NaF of 19 immunoreactive proteins. Enzyme assay and immunochemical data showed an inhibition of the moulting-specific inorganic pyrophosphatase activity by 41% and a decreased expression in NaF-treated larvae, indicating its significance in the moulting process. A protein spot associated with NaF inhibition was isolated and identified by peptide mass spectrometry and bioinformatics approaches to be a member of 3-hydroxyacyl-CoA dehydrogenase/short-chain dehydrogenase enzyme families. These results have implications for the identification of proteins specific to the moulting process as potential chemotherapeutic targets.

Amino Acid Sequence↗

The V kappa III subgroup light chain proteins in AL amyloidosis & autoimmune diseases.

BACKGROUND & OBJECTIVES: Light chain associated amyloidosis (AL) is characterized by extracellular deposition of immunoglobulin light chain and its fragments. In vitro and in vivo studies have shown that some light chains are nonamyloidogenic and nonnephrotoxic, whereas others are potentially amyloidogenic. Some light chains are prone to be deposited as rheumatoid materials, and also as nodular amorphous aggregates (light chain deposition diseases). These findings suggest that specific sequence element(s) may control the various kinds of light chain associated diseases. In this study we tried to identify such sequence element(s). METHODS: Two Bence Jones proteins (BJPs), NIG93 and NIG2 of subgroup V kappa III, were characterized and compared with other members of the same subgroup whose sequences are available in the data base. RESULTS: Both NIG93 and NIG2 proteins had sequences characteristics of V kappa IIIa as distinguished from V kappa IIIb, subsubgroup proteins. They also contained several novel substitutions, such as Met-37, Leu-40, Val-58, and IIe-85 in NIG93, and Val-2, His-29, Arg-50, and Ile-72 in NIG2. The data accumulated at present indicate that all members of the V kappa IIIa subsubgroup are related to either AL amyloidosis or rheumatoid arthritis, whereas the V kappa IIIb proteins are related to autoimmune diseases. INTERPRETATION & CONCLUSION: These observations indicate that subgroup-specific residues might be critical for light chain pathogenesis, at least for the V kappa III proteins. Point mutations within these proteins may be another structural element controlling their conformation as well as their pathogenic aggregation.

Amino Acid Sequence↗

NACP/alpha-synuclein and tau constitute two distinctive subsets of filaments in the same neuronal inclusions in brains from a family of parkinsonism and dementia with Lewy bodies: double-immunolabeling fluorescence and electron microscopic studies.

The co-localization of NACP/alpha-synuclein and tau epitopes was examined in the brain stem and hippocampal formation in two patients from a family of autosomal dominant parkinsonism and dementia with Lewy bodies (LBs) without two reported missense mutations in the NACP gene. Double-labeling immunofluorescence study revealed that some brain stem LBs, cortical LBs, pale bodies, Lewy-related neurites, and neurofibrillary tangles expressed both NACP epitopes and the PHF tau AT8 epitope. Double-immunolabeling electron microscopy demonstrated that the NACP antibody selectively labeled 9- to 13-nm-thick straight filaments (LB filaments), whereas AT8 recognized twisted tubules with 80-to 100-nm-interval constrictions in the same neuronal inclusions. We show that NACP and tau aggregate into different filamentous components even if both proteins are incorporated into the same inclusions.

Adult↗

Structural relationship of lambda-type light chains with AL amyloidosis.

Three human amyloidogenic Bence Jones proteins, NIG76 VlambdaII, NIG204 VlambdaI, and NIG250 VlambdaV, were characterized. In a comparative study, three amino acids, Ser-25a, Thr-68, and Val-95, were found to be common to amyloidogenic proteins of the VlambdaII subgroup. NIG204 had an insertion of Pro residue following position 30 (30a). Proteins having an insertion at this position are invariantly amyloidogenic. NIG250 had a characteristic VlambdaV VL domain, with Mcg+ and KERN+ CL domain isotypes. Following the protein DEL, this is the second example of this subgroup. No common residue is found in the other subgroup proteins but unique substitutions do occur. It would seem that any substitution that causes an alteration in the protein conformation may lead to its being more prone to association with the amyloid processes.

Amino Acid Sequence↗

Structural relationship of kappa-type light chains with AL amyloidosis: multiple deletions found in a VkappaIV protein.

Two amyloidogenic Bence Jones proteins (Am37 VkappaIV and NIG1 VkappaI) and one non-amyloidogenic protein (NIG26 VkappaIII) were characterized. The protein Am37 had four deletions when compared with the translated germ-line gene sequence: two Ser residues following position 27 (27e, 27f) in CDR1 and two amino acids Pro-44, and Tyr-49 in FR2 were deleted. A strictly conserved salt-bridge-forming amino acid, Asp-82, was replaced by the hydrophobic residue Leu. In a comparative study of amyloidogenic and non-amyloidogenic proteins, five amino acids (Ser-10, Ala-13, Ser-65, Gln-90, and Ile-106) were found to be unique to NIG1 and several other amyloidogenic proteins. Additional substitutions also occur within these proteins. These substitutions might be significant in altering protein folding as well as in contributing to their aggregation as amyloid fibrils.

Amino Acid Sequence↗