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Abstract: A new lectin, BfL, was purified from Bauhinia forficata seeds by ammonium sulfate fractionation, DEAE-Sephadex ion exchange chromatography, Sepharose-4B and chitin affinity chromatographies and Superdex 75 size exclusion chromatography. The molecular homogeneity and purity of BfL were assessed by reversed-phase HPLC. BfL appeared as a single band of approximately 27.0kDa on SDS-PAGE under non-reducing and reducing conditions, and its molecular weight was determined to be 27,850Da by LC/ESI-MS. BfL is a glycoprotein with a carbohydrate content of 6.24% determined by the phenol–sulfuric acid method. Fetuin, asialofetuin, thyroglobulin and azocasein inhibited the hemagglutinating activity of BfL, whereas saccharides did not. BfL hemagglutinating activity was stable at 100°C for 30min, pH-dependent, with the highest activity at pH 6.0, and metal-independent. The primary structure of BfL shows similarity with other lectins from the genus Bauhinia. Deconvolution of the BfL circular dichroism (CD) spectrum indicated the presence of α-helix and β structures. BfL increases coagulation time, but this effect is not related to human plasma kallikrein or human factor Xa inhibition. BfL also inhibits ADP- and epinephrine-induced platelet aggregation in a dose-dependent manner and is the only currently described lectin from Bauhinia that exhibits anticoagulant and antiplatelet aggregating properties. [Copyright &y& Elsevier]

Summary: Centromeres form the site of chromosome attachment to microtubules during mitosis. Identity of these loci is maintained epigenetically by nucleosomes containing the histone H3 variant CENP-A. Propagation of CENP-A chromatin is uncoupled from DNA replication initiating only during mitotic exit. We now demonstrate that inhibition of Cdk1 and Cdk2 activities is sufficient to trigger CENP-A assembly throughout the cell cycle in a manner dependent on the canonical CENP-A assembly machinery. We further show that the key CENP-A assembly factor Mis18BP1HsKNL2 is phosphorylated in a cell cycle-dependent manner that controls its centromere localization during mitotic exit. These results strongly support a model in which the CENP-A assembly machinery is poised for activation throughout the cell cycle but kept in an inactive noncentromeric state by Cdk activity during S, G2, and M phases. Alleviation of this inhibition in G1 phase ensures tight coupling between DNA replication, cell division, and subsequent centromere maturation. [Copyright &y& Elsevier]

Abstract: Lectins, proteins which recognize selectively carbohydrates, have been used as affinity chromatography to purify glycoproteins. Cratylia mollis seed lectin (Cramoll 1,4), of mannose/glucose binding class, immobilized on Sepharose CL-4B, was used as affinity matrix. This paper describes the purification by Cramoll 1,4-Sepharose matrix, and characterization of an anti-platelet and anticoagulant soybean (Glycine max) protein, ApcSP, and its in vitro platelet antiaggregation and anticoagulant activities. SDS-PAGE of ApcSP purified under reducing condition revealed a single glycosilated band of 51kDa. The N-terminal 10-residue sequence of ApcSP is EGQFGPMIQS, distinct to other soybean seed proteins, such as peroxidase, lectin, 2S albumin and trypsin inhibitor. Deconvolution of CD spectrum indicated 35% α-helix, 17% β-strand, 22% turn and 26% unordered structure; ApcSP fluorescence spectrum showed a maximum emission around 339nm. The hemostatic parameters revealed inhibition of collagen (p <0.001), thrombin (p <0.05) and ADP (p <0.001)-induced platelet aggregation in the presence of ApcSP (2μM), in relation to positive control. The soy protein prolonged the blood coagulation time (activated partial thromboplastin time, more affected, and prothrombin time). The results indicated that immobilized Cramoll 1,4 lectin has the potential to isolate soybean glycoproteins and ApcSP may be important for anti-thrombotic and anticoagulant therapy. [ABSTRACT FROM AUTHOR]