Ribosomal protein S18 identified as a cofilin-binding protein by using phage display library.

We previously reported that an actin-binding protein, cofilin, is involved in superoxide production, phagocytosis, and chemotaxis in activated phagocytes through cytoskeletal reorganization. To elucidate the functions of cofilin in greater detail we tried to identify cofilin-binding proteins by using a phage-displayed cDNA library constructed from human brain mRNAs. Several phage clones capable of binding to cofilin were obtained, and the phage with the strongest binding affinity contained the C-terminal half of ribosomal protein S18.

LIM kinase 1 modulates opsonized zymosan-triggered activation of macrophage-like U937 cells. Possible involvement of phosphorylation of cofilin and reorganization of actin cytoskeleton.

We have previously reported that cofilin, an actin-binding protein, plays an important role in phagocyte functions, such as respiratory burst, phagocytosis, and chemotaxis. On the other hand, it was recently found that LIM motif-containing kinase (LIMK) phosphorylates cofilin. In this work, we investigated the roles of LIMK in activated phagocytes.

U73122 inhibits the dephosphorylation and translocation of cofilin in activated macrophage-like U937 cells.

Cofilin, an actin-binding protein, plays an important role in the migration, phagocytosis, and superoxide production of activated phagocytes through cytoskeletal reorganization. In unstimulated phagocytes, cofilin is a major phosphoprotein. However, upon activation, the phosphoprotein is dephosphorylated and translocated from cytosol to plasma membranes.

Appearance of sodium dodecyl sulfate-stable amyloid beta-protein (Abeta) dimer in the cortex during aging.

We previously noted that some aged human cortical specimens containing very low or negligible levels of amyloid beta-protein (As) by enzyme immunoassay (EIA) provided prominent signals at 6 approximately 8 kd on the Western blot, probably representing sodium dodecyl sulfate (SDS)-stable Abeta dimer. Re-examination of the specificity of the EIA revealed that BAN50- and BNT77-based EIA, most commonly used for the quantitation of Abeta, capture SDS-dissociable Abeta but not SDS-stable Abeta dimer. Thus, all cortical specimens in which the levels of Abeta were below the detection limits of EIA were subjected to Western blot analysis.

Quantitation of amyloid beta-protein (A beta) in the cortex during aging and in Alzheimer's disease.

In this study we sought to learn about when and how amyloid beta-protein (A beta) accumulates in the cortex of normal individuals and about the difference in the A beta accumulation between normal aged and Alzheimer's disease (AD) brains. From consecutive autopsy cases and AD cases, hippocampus CA1 and occipitotemporal cortex T4 were sampled for A beta quantitation by the well characterized two-site enzyme immunoassays (EIAs). There was a strong tendency toward A beta 42 accumulation between the ages of 50 and 70 years in T4 and a little later in CA1.

Structural study of N-linked sugar chains of sheep erythrocyte membrane glycoproteins.

Our previous study showed that non-reducing terminal galactose residues of N-linked sugar chains present in sheep erythrocyte membrane glycoproteins are important for rosette formation with T lymphoblastic cells [Ogasawara et al. (1995) Immunol Lett 48: 35-38]. As a first step to elucidate the significant structures of sugar chains involved in rosette formation, we analysed N-linked sugar chains released from the membrane glycoproteins by hydrazinolysis.

Role of terminal galactose residues in N-linked sugar chains of sheep erythrocyte membrane glycoproteins in rosette formation with T lymphocytes.

In this study, we found that rosette formation of T lymphoblastic Molt-3 cells with sheep erythrocytes is inhibited by addition of membrane glycoproteins which were solubilized from sheep erythrocyte ghosts by the lithium diiodosalicylate extraction methods. Their rosetting inhibitory activity was markedly reduced by digestion with N-glycanase, but not with O-glycanase. The inhibitory activity was also reduced by beta-galactosidase digestion, while it was enhanced by desialylation.

cDNA cloning and expression of Bauhinia purpurea lectin.

Bauhinia purpurea lectin (BPA) was purified from seeds of B. purpurea alba. The purified lectin was digested with an endoproteinase, Asp-N, or trypsin and then the amino acid sequences of the resultant fragments were analyzed.

Purification and characterization of a carbohydrate-binding peptide from Bauhinia purpurea lectin.

In order to examine the correlation between the amino acid sequence and sugar binding specificity of Bauhinia purpurea lectin (BPA), a galactose and lactose binding lectin, a peptide which interacts with lactose was purified from an Asp-N endoproteinase digest of BPA by means of affinity chromatography on a column of lactose-Sepharose. The amino acid sequence of this peptide is Asp-Thr-Trp-Pro-Asn-Thr-Glu-Trp-Ser. A tryptic fragment having the ability to interact with lactose was also purified and found to contain the above sequence, consisting of 9 amino acids.