The insulin A and B chains contain sufficient structural information to form the native molecule

Refolding studies show that native insulin can be reformed from A and B chains only. This suggests that the A and B chains contain the necessary structural information and that the C peptide is not required for this process.     

A fluorogenic method for the demonstration of human serum 5′-nucleotide phosphodiesterase isozymes after polyacrylamide gel electrophoresis

A rapid fluorogenic method for the demonstration of 5′-nucleotide phosphodiesterase in human serum has been developed. This method uses the substrate 4-methylumbelliferyl 5′-thymidylate impregnated in agarose gels or filter paper strips. Zymograms are developed in less than 30 min at 25°C, and the sensitivity of this method has been compared with that of the indigogenic method.     

几种常用杀虫剂对蚜虫天敌——瓢虫的影响

作者等就11种常用杀虫剂对蚜虫的重要天敌——瓢虫进行了毒性测定,观察了它们对瓢虫的各个虫态的影响。 供试药剂 20％乐果乳剂、50％敌敌畏乳剂、50％对硫磷乳剂、50％内吸磷乳剂、25％三硫磷乳剂、50％杀螟硫磷乳剂、50％磷胺液剂、20％酚开普敦乳剂、6％丙体六六六乳剂、6％丙体六六六可湿性粉(W、P)、2.5％鱼籐精乳剂。 供试瓢虫 异色瓢虫Leis axyridis,室内饲养;龟纹瓢虫Propylaea japonica,田间采回。     

Expression of the high capacity calcium-binding domain of calreticulin increases bioavailable calcium stores in plants

Modulation of cytosolic calcium levels in both plants and animals is achieved by a system of Ca²⁺-transport and storage pathways that include Ca²⁺ buffering proteins in the lumen of intracellular compartments. To date, most research has focused on the role of transporters in regulating cytosolic calcium. We used a reverse genetics approach to modulate calcium stores in the lumen of the endoplasmic reticulum. Our goals were two-fold: to use the low affinity, high capacity Ca²⁺ binding characteristics of the C-domain of calreticulin to selectively increase Ca²⁺ storage in the endoplasmic reticulum, and to determine if those alterations affected plant physiological responses to stress. The C-domain of calreticulin is a highly acidic region that binds 20–50 moles of Ca²⁺ per mole of protein and has been shown to be the major site of Ca²⁺ storage within the endoplasmic reticulum of plant cells. A 377-bp fragment encoding the C-domain and ER retention signal from the maize calreticulin gene was fused to a gene for the green fluorescent protein and expressed in Arabidopsis under the control of a heat shock promoter. Following induction on normal medium, the C-domain transformants showed delayed loss of chlorophyll after transfer to calcium depleted medium when compared to seedlings transformed with green fluorescent protein alone. Total calcium measurements showed a 9–35% increase for induced C-domain transformants compared to controls. The data suggest that ectopic expression of the calreticulin C-domain increases Ca²⁺ stores, and that this Ca²⁺ reserve can be used by the plant in times of stress.     

Molecular taxonomy of Camellia (Theaceae) inferred from nrITS sequences

Camellia, comprising more than 200 species, is the type genus of the family Theaceae. Currently, the interspecies relationship of the economically important genus is still a matter of great debate and controversy. In an attempt to help settle this dispute using molecular phylogeny, we analyzed ITS sequences of 112 species of Camellia. The maximum parsimony and Bayesian trees grouped these species into eight major clades and four isolates. The current study supported the monophyly of sections Thea and Furfuracea, a merged section of Theopsis and Eriandra and the formation of section Oleifera by H, -t. Chang (Flora of Reipulicae Popularis Sinicae. Tomus 49 (3), Science Press, China). The study suggested the polyphyletic nature of the sections Camellia, Paracamellia, Pseudocamellia, and Tuberculata and the paraphyletic nature of the section Chrysantha but did not support the sectional status of the three small sections, Archecamellia, Piquetia, and Sterocarpus. We also discuss the results in terms of morphology, geographic distribution and the results from an earlier molecular phylogeny analysis.     

A possible strategy against head and neck cancer: in silico investigation of three-in-one inhibitors

Overexpression of epidermal growth factor receptor (EGFR), Her2, and uroporphyrinogen decarboxylase (UROD) occurs in a variety of malignant tumor tissues. UROD has potential to modulate tumor response of radiotherapy for head and neck cancer, and EGFR and Her2 are common drug targets for the treatment of head and neck cancer. This study attempts to find a possible lead compound backbone from TCM Database@Taiwan (http://tcm.cmu.edu.tw/) for EGFR, Her2, and UROD proteins against head and neck cancer using computational techniques. Possible traditional Chinese medicine (TCM) lead compounds had potential binding affinities with EGFR, Her2, and UROD proteins. The candidates formed stable interactions with residues Arg803, Thr854 in EGFR, residues Thr862, Asp863 in Her2 protein, and residues Arg37, Arg41 in UROD protein, which are key residues in the binding or catalytic domain of EGFR, Her2, and UROD proteins. Thus, the TCM candidates indicated a possible molecule backbone for evolving potential inhibitors for three drug target proteins against head and neck cancer.

An animated interactive 3D complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:35     

Long-term Therapeutic Effects of Extracorporeal Shock Wave-Assisted Melatonin Therapy on Mononeuropathic Pain in Rats

We evaluated the ability of extracorporeal shock wave (ECSW)-assisted melatonin (Mel) therapy to offer an additional benefit for alleviating the neuropathic pain (NP) in rats. Left sciatic nerve was subjected to chronic constriction injury (CCI) to induce NP. Animals (n?=?30) were randomized into group 1 (sham-operated control), group 2 (CCI only), group 3 (CCI?+?ECSW), group 4 (CCI?+?Mel) and group 5 (CCI?+?ECSW?+?Mel). By days 15, 22 and 29 after CCI, the thermal paw withdrawal latency (TPWL) and mechanical paw withdrawal threshold (MPWT) were highest in group 1, lowest in group 2, significantly higher in group 5 than in groups 3 and 4, but they showed no difference between the later two groups (all p?<?0.0001). The protein expressions of inflammatory (TNF-α, NF-κB, MMP-9, IL-1ß), oxidative-stress (NOXs-1, -2, -4, oxidized protein), apoptotic (cleaved-caspase3, cleaved-PARP), DNA/mitochondrial-damaged (γ-H2AX/cytosolic-cytochrome C), microglia/astrocyte activation (ox42/GFAP), and MAPKs [phosphorylated (p)-p38, p-JNK, p-ERK] biomarkers in dorsal root ganglia neurons (DRGs) and in spinal dorsal horn were exhibited an opposite pattern of TPWL among the five groups (all p?<?0.0001). Additionally, protein expressions of Nav.1.3, Nav.1.8 and Nav.1.9 in sciatic nerve exhibited an identical pattern to inflammation among the five groups (all p?<?0.0001). The numbers of cellular expressions of MAPKs (p-ERK1/2+/peripherin?+?cells, p-ERK1/2+/NF200?+?cells and p-JNK+/peripherin?+?cells, p-JNK+/NF200?+?cells) and voltage-gated sodium channels (Nav.1.8+/peripherin?+?cells, Nav.1.8+/NF200?+?cells, Nav.1.9+/peripherin?+?cells, Nav.1.9+/NF200?+?cells) in small and large DRGs displayed an identical pattern to inflammation among the five groups (all p?<?0.0001). In conclusion, the synergistic effect of combined ECSW-Mel therapy is superior to either one alone for long-term improvement of mononeuropathic pain-induced by CCI in rats.

     

Activity change during unfolding of bovine pancreatic ribonuclease A in guanidine

Bovine pancreatic ribonuclease A loses almost completely its activity in 2-3 M guanidine, whereas only very slight conformational changes can be detected when following its unfolding by changes in its intrinsic fluorescence at 305 nm and ultraviolet absorbance at 287 nm. Reactivation on diluting out the denaturant is a time-dependent process, indicating that the inactivation is not due to inhibition by a reversible association of the enzyme with guanidine. The kinetic method of following the substrate reaction, in the presence of the denaturant previously proposed for use in the study of rapid inactivation reactions (Tian, W.X. and Tsou, C.-L. (1982) Biochemistry 21, 1028-1032), is applied to examine the inactivation rates of this enzyme during guanidine denaturation, and these have been compared with the unfolding rates as followed by fluorescence and absorbance changes. It is shown that during the unfolding of this enzyme in guanidine, the inactivation of the enzyme occurs within the dead time of mixing in a stopped-flow apparatus and is at least several orders of magnitude faster than the unfolding reaction as detected by the optical parameters. It appears that, as in the case of creatine kinase reported previously, the active site of a small enzyme stabilized by multiple disulfide linkages, such as ribonuclease A, is also situated in a region which is much more liable to being perturbed by denaturants than is the molecule as a whole.