Protein and Peptide Letters - Volume 13, Issue 4, 2006

In the present study, two phytocystatins were purified to homogeneity as peaks I and II with molecular weights of 19 kDa and 17 kDa, respectively, as determined by SDS-PAGE and mass spectrometry. Both PMCs I and II were purified with a greater than 1000-fold purification and overall yield of about 16-18%. The effect of urea on PMC I and II was analysed by fluorescence and Circular Dichroism (CD) spectroscopy. Fluorescence Read More

We have analyzed a series of peptides derived from the C-terminus of α-synuclein for chaperone-like activity. Specifically, a cyclic peptide generated by introducing a disulfide bond was observed to increase chaperone-like activity. This is the first example of a disulfide-crosslinked peptide that exhibits activity against protein aggregation and activity loss.

The expression of membrane proteins has been the bottleneck for their structural studies. Recently, we developed a method to obtain milligram quantities of isotope-labeled seven transmembrane G-protein coupled cannabinoid (CB) receptor fragment in E. coli. In order to verify this method and confirm the recombinant isotope-labeled CB2 fragment, 3D hetero-nuclear NMR techniques were used to analyze the structure of t Read More

Chemico-enzymatic synthesis and cloning in Esherichia coli of an artificial gene coding human glucagon was performed. Recombinant plasmid containing hybrid glucagons gene and intein Ssp dnaB from Synechocestis sp. was designed. Expression of the obtained hybrid gene in E. coli, properties of the formed hybrid protein, and conditions of its autocatalytic cleavage leading to glucagon formation were studied.

In this report we show the purification to homogeneity and a partial characterization of a new odorant-binding protein from Canis familiar (CfOBP) nasal mucosa. In addition, we report preliminary data on the utilization of CfOBP as a probe for the development of a refractive index-based biosensor.

We examined the production and secretion of fusion constructs containing α-N-acetylglucosaminidase, the enzyme deficient in Sanfilippo B, and either wildtype TAT or modified TAT in cultured Spodoptera frugiperda cells. All constructs exhibited successful expression of active enzyme, suggesting the future possibility of utilizing TAT/α-Nacetylglucosaminidase chimerae in enzyme replacement therapy.

Purified human liver arylsulfatase A (ASA) as well as an ASA peptide (residues 28-39) were sulfated by tyrosyl protein sulfotransferase in vitro. The media, but not the cell lysate, of normal human fibroblasts contained a tyrosine sulfated protein (pI = 4.5-5.5). This protein was not present in either media or cell lysate of human fibroblasts lacking ASA protein. These results suggest that tyrosine sulfation facilitates secretion of Read More

Uricase from bovine kidney, purified to homogeneity level, had a molecular weight of 70 kDa. The apparent Km and Vmax values for uric acid hydrolysis were 0.125 mM and 102 IU mg-1 protein respectively. The activation energy requirement for uric acid hydrolysis by uricase and inactivation of enzyme were 11.6 and 14.5 kJ/M respectively. Both enthalpy (Δ H*) and entropy of activation (Δ S*) for uricase activity we Read More

Rho Kinase I (ROCK I) is a serine/threonine kinase that is involved in diverse cellular signaling. To further understand the physiological role of ROCK I and to identify and develop potent and selective inhibitors of ROCK I, we have overexpressed and purified a constitutively active dimeric human ROCK I (3-543) kinase domain using the Sf9- baculovirus expression system. In addition, using a limited proteolysis technique, we have i Read More

In this review we summarize the current state, history, future, mutation tendency and species susceptibility of influenza A virus proteins based on our probabilistic analyses on amino acid pairs, and compare the current state of influenza A virus proteins with that of proteins which we have studied in the past.

Assembly of α-synuclein (α-Syn) into neurotoxic oligomers and fibrils is an important pathogenic feature of Parkinson's disease. Studying the early events of α-Syn aggregation, such as oligomerization and nucleation, is indispensable to understanding the complicated process. Here, photo-induced cross-linking of unmodified proteins (PICUP) technique is applied to elucidate the early-stage oligomerization of α-Syn. Results s Read More

In this paper, the tertiary structures of protein chains of heterocomplexes were mapped to 2D networks; based on the mapping approach, statistical properties of these networks were systematically studied. Firstly, our experimental results confirmed that the networks derived from protein structures possess small-world properties. Secondly, an interesting relationship between network average degree and the netwo Read More

This review focuses on the structure, function and pathological role of leukocyte function-associated antigen-1 (LFA-1) which is a heterodimeric protein consisting of two subunits. LFA-1 plays a most important role in the immune system including adhesion, extravasation, migration, apoptosis, cytotoxicity, cytokine production, and proliferation of lymphocytes. Therefore, T-cell activation can be suppressed by blocking ICAM-1/LF Read More

Both H2O2 and NO can act as apoptogens, triggering apoptosis in many cells. They are also well known inhibitors of caspases, essential enzymes in apoptosis. The differences between these two agents as apoptosis inducers and how caspases mediate apoptosis with these inhibitory agents is still unclear. Consistent with the previous reports, these two agents induced apoptosis accompanied by caspase activation with limitation of Read More

L-Arginine kinase (AK; ATP:L-arginine N-phosphotransferase; EC 2.7.3.3) catalyzes the reversible transphosphorylation between N-phospho-L-arginine (PArg) and ATP thus buffering cellular ATP levels. AK was purified from the leg muscle of the locust Migratoria manilensis by Sephacryl S-200 HR gel filtration chromatography and DEAE Sepharose CL-6B fast flow anion exchange chromatography to an apparent homogeneit Read More

Norepinephrine-stimulated skin secretions from the Sante Fe frog Leptodactylus laticeps contained high concentrations of a peptide, termed laticeptin, with the primary structure Gly-Val-Val-Asp-Ile-Leu-Lys-Gly-Ala-Ala-Lys- Asp-Leu-Ala-Gly-His-Leu-Ala-Thr-Lys-Val-Met-Asn-Lys-Leu.NH2. Laticeptin inhibited the growth of selected Gramnegative bacteria but the lack of activity against Gram-positive bacteria and the very lo Read More

Yeast tyrosyl-tRNA synthetase (yTyrRS) has been crystallized by the vapor diffusion method in the presence of its cognate tRNATyr. The crystals belong to a tetragonal space group P41212 with cell dimensions of a = b = 63.85 Å, and c = 330.3 Å. The asymmetric unit contains one molecule each of yTyrRS and tRNATyr (one-half of a 2:2 complex). Xray diffraction data have been collected up to 2.5 Å resolution.