Protein and Peptide Letters - Volume 10, Issue 2, 2003

Dynamical properties of macromolecules are increasingly being recognized as significantly contributing to biological functions, including catalysis, regulation of activity, etc. In this review, theoretical approaches to the study of dynamics of biological systems and their application are discussed. In particular, simplified models for the normal mode analysis are described.

We have synthesised the CXC chemokine receptor 4 (29-39) peptide, CXCR4{29-39}. This peptide is located in the N-terminal region of the receptor and is likely to be involved in the docking step of the receptor interaction with its natural ligand stromal cell-derived factor-1 chemokine, SDF-1. Preliminary experiments, performed in the presence of micellar detergents to model a membrane-like environment, show that the (1-17 Read More

The binding energetics of actinidin to chicken cystatin was determined from fluorometric titrations at different temperatures. It is shown that the association of actinidin with cystatin is both enthalpically and entropically driven, with a negative change in the heat capacity. The molecular basis of these contributions are analyzed within the framework of surface-area models, using a 3D model of the actinidin-cystatin complex, w Read More

Formylpeptide receptors are well-characterized receptors which participate in host defense responses of neutrophils. We designed and synthesized chemotactic peptide analog with pbenzoylphenylalanine (Bpa) and biotin to probe structural and mechanistic aspects of peptide-receptor interaction. These peptides possess biological activities which were dependent upon spacer residue length of and Bpa position. The cova Read More

Binding of mercury to BSA and Ovalbumin was investigated by Differential Pulse Voltammetry. The method relies on the direct monitoring of peak current variation due to mercury oxidation in the presence of these two albumins. Linear calibration graphs were obtained for both BSA and Ovalbumin in concentrations ranging from 2.49 x 10 -7 to 19.6 x 10 -9 mol L -1. The acquired data was used to quantify these two protei Read More

A novel lectin, denominated ACLEC, was isolated from Annona coriacea seeds, belonging to the Annonaceae family. The lectin presented one protein band in SDS-PAGE of 14 kDa. Of the sugars tested, Dglucose and D-mannose were the best inhibitors. A search sequence database showed that ACLEC had homology with other plant lectins, belonging to leguminous lectin family.

An efficient fusion expression system with a small fusion partner, His6-tagged N-terminal fragment of staphylococcal nuclease R, has been constructed and tested with two genes. The results show that the system is not only suitable for overexpression of small proteins and peptides but simplifies purification of target proteins and peptides. The study also provides a practical method for preparation of isotope-labeled prot Read More

Resin coupled with m-aminophenylbornic acid was used to isolate a glycosylated component from homogenate of earthworm (Eisenia fetida). The fraction showed a single band on SDS-PAGE with a molecular weight of 34,193 Da determined by mass spectroscopy. The N-terminal region is AQVCCPDI, different from those of earthworm fibrinolytic enzymes reported previously (Nakajima et al. 1993). This glycosylated compon Read More

The lectin from the seeds of Canavalia ensiformis (ConA) and Dioclea guianensis (DguiL) was tested upon its renal effects using the isolated perfusion rat kidney method. Both lectins (10μg/ml) affected perfusion pressure and renal vascular resistance, but DguiL showed a much greater action than ConA. However, ConA, but not DguiL, affected potassium tubular transport.

The influence of glycerol, sorbitol, glucose and sucrose, on the refolding and reactivation courses of guanidine-denatured arginine kinase was studied. Glycerol, sucrose, and sorbitol, but not glucose, could improve the reactivation of the denatured arginine kinase, although in all cases aggregation was inhibited. Size exclusion chromatography showed that misfolded products were still formed during polyol-assisted refol Read More

An N-terminal polypeptide (XVAX2-P104) of the XVAX2 protein, which is involved in controlling the dorsoventral patterning of the retina in Xenopus laevis, was expressed and purified as a Histagged fusion protein (pHis-XVAX2-P104), and it was employed to generate an anti-XVAX2 antibody in New Zealand white rabbits. ELISA analysis shows that the titer of the antibody is as high as ∼1:100,000. The antibody could specifically r Read More

DNA fragmentation factor 45 (DFF45) regulates DNase DFF40 as its inhibitor and chaperone. It was reported that the N-terminal domain (NTD) of DFF45 alone is disordered and DFF40 is necessary as a mutual chaperone for the folding of NTD. However, here we reported the crystallization of DFF45 NTD. These crystals diffract to 9Å using a synchrotron radiation source. In spite of the low resolution, the demonstration of crystal Read More