The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine re...

Neuromedin U receptors (provisional nomenclature as recommended by NC-IUPHAR [30]) are activated the endogenous 25 amino acid peptide neuromedin (neuromedin U-25, NmU-25), a originally isolated from pig spinal cord [92]. In humans, NmU-25 appears to be sole product of precursor gene (NMU, P48645) showing broad tissue distribution, but which is expressed at highest levels in upper gastrointestin...

Prothyrotropin-releasing hormone (pro-TRH) is initially cleaved by the prohormone convertase-1/3 (PC1/3) in the trans-Golgi network generating N- and C-terminal intermediate forms that are then packed into secretory vesicles. However, it is not known whether these peptides are differentially sorted within the secretory pathway. This is of key importance because the processing products of severa...

fabms analysis of t-lb peptide before and after one cycle of edman degradation indicated an unblocked n-terminal thr residue for this tryptic peptide. in contrast , our data showed a molecular protonated ion, mh + for t- la peptide at 655 mass units (mu) which is 42 mu higher than the mh ion of t- 1b peptide. in addition, t- la peptide was not amenable to one cycle of manual edman degradation. ...

Protoporphyrinogen oxidase (EC 1-3-3-4), the 60-kDa membrane-bound flavoenzyme that catalyzes the final reaction of the common branch of the heme and chlorophyll biosynthesis pathways in plants, is the molecular target of diphenyl ether-type herbicides. It is highly resistant to proteases (trypsin, endoproteinase Glu-C, or carboxypeptidases A, B, and Y), because the protein is folded into an ex...

Peptides are in great demand the pharmaceutical arena and a majority of these peptides contain 20 or more amino acids. They infrequently synthesised using fragment condensation approach. A key limitation adopting this approach commonly is that protected peptide fragments with high purity often required prior to final steps. It hypothesized understanding hydrophobic nature acids will assist desi...

N-terminal peptide derivatization strategies used in conjunction with tandem mass spectrometry to yield simplified fragmentation patterns have shown limited success for the de novo sequencing of multiply charged peptides, including those predominantly formed in LC-ESI-MS experiments. Significant proton mobilization occurs for multiply charged peptides upon collisional activation, resulting in t...

Two classes of paralytic toxins were isolated from the venom of Agelenopsis aperta and their chemical and larvicidal properties characterized. Five acylpolyamine toxins (alpha-agatoxins) of molecular masses 452, 488, 489, 504, and 505 Da produce immediate but reversible paralysis in Manduca sexta following injection. Six insecticidal peptides (mu-agatoxins) produce a gradual but irreversible pa...

The DNA binding activity of p53 is crucial for its tumor suppressor function and is subject to tight regulation. Previous studies revealed that the inhibitory function of the p53 C terminus is implicated in the latent, low affinity sequence-specific DNA binding activity of p53 in the uninduced state. Sequence-specific DNA binding of p53 has been shown to be activated by several posttranslationa...

C-C chemokine receptor 5 (CCR5) is a major co-receptor molecule used by HIV-1 to enter cells. This led the hypothesis that stimulating an antibody response would block HIV with minimal toxicity. Here, X-ray crystallographic studies of anti-CCR5 RoAb13 together two peptides were undertaken: one peptide 31-residue containing PIYDIN sequence and other PIDYIN alone, where part N-terminal region CCR...