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Introduction: Apomorphine is used to treat OFF periods in Parkinson's disease (PD) patients. AZ-009 is a novel apomorphine formulation that delivers a thermally-generated aerosol to the deep lung via inhalation with a single breath., Methods: Part A was a randomized, placebo-controlled, double-blind study investigating the safety and pharmacokinetics of multiple ascending doses of AZ-009. PD patients (n = 24) received placebo or 2, 3 or 4 mg AZ-009 once daily for 5 days, followed by three times daily for 2 days with 2 h between doses. Part B was a double-blind crossover study in 8 PD patients who experience OFF periods. During an OFF state, patients received 4 mg AZ-009 and placebo on two consecutive days in a randomized order. MDS-UPDRS III and ON/OFF state were assessed pre- and post-dose., Results: Three times daily dosing with 2, 3 and 4 mg AZ-009 was relatively well tolerated with no apparent accumulation or changes in safety profile. Mild and transient throat irritation and cough were reported most often. AZ-009 was rapidly absorbed with median T max between 1 and 2 min. When corrected for placebo response, the maximum effect of 4 mg AZ-009 based on MDS-UPDRS III scores was observed at 10 and 30 min post-dose with mean (SD) reductions of 6.8 (9.4) and 6.1 (9.1) points respectively. Whereas 0% of patients turned ON after placebo, 50% turned ON 10 min after 4 mg AZ-009 treatment., Conclusion: AZ-009 is rapidly systemically absorbed and safe to dose three times daily. AZ-009 could provide a faster-acting and easier to use formulation than currently available therapies., (Copyright © 2022. Published by Elsevier Ltd.)

Background: Inhalation of apomorphine could be a faster-acting and more user-friendly alternative to subcutaneous injection for treating off periods in Parkinson's disease (PD)., Objective: The aim of this study was to compare the safety and pharmacokinetics of inhaled apomorphine (AZ-009) with subcutaneous apomorphine (APO-go PEN) in healthy volunteers (HVs) and to examine the safety, pharmacokinetics, and efficacy of AZ-009 in patients with PD., Methods: In part A of this study, eight HVs received 1 mg AZ-009 and 2 mg subcutaneous apomorphine in a randomized crossover manner. In the subsequent single ascending dose parts in HVs (part B, n = 16) and patients with PD (part C, n = 25), participants were randomized to placebo or AZ-009 up to 4 mg. In patients, after medication withdrawal, Movement Disorder Society-Unified Parkinson's Disease Rating Scale part III and on/off states were assessed predose and postdose., Results: AZ-009 was rapidly absorbed with peak plasma concentrations at 2 minutes, as compared to 30 minutes for subcutaneous apomorphine. Adverse events for AZ-009 were comparable to subcutaneous apomorphine, except for mild and transient throat irritation. Adverse events limited AZ-009 dose escalation in HVs to 3 mg. Patients tolerated up to 4 mg. In patients with PD, 2, 3, and 4 mg AZ-009 reduced mean Movement Disorder Society-Unified Parkinson's Disease Rating Scale part III score (standard deviation) by 10.7 (13.6), 12.8 (7.9), and 10.3 (3.7) points, respectively, compared to 4.8 (4.9) after placebo at 10 minutes postdose. The percentage of patients achieving full on within 45 minutes postdose increased dose dependently: 0% (placebo), 17% (2 mg), 50% (3 mg), and 83% (4 mg)., Conclusions: AZ-009 appears to be a rapid-acting and reasonably well-tolerated formulation for treating off periods. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Activation of erythropoietin (EPO) receptor (EPOR) by a small peptide (ERP) was reported previously. ERP binds to a different receptor site than EPO, and binding of ERP does not change the dissociation constant and maximal binding for EPO binding to the receptor. The extracellular binding site for ERP is now characterized. The site is located in the membrane proximal, extracellular part of the receptor. ERP binds to a region on the EPOR that contains the same sequence as ERP. It is speculated that ERP binds to its identical sequence on EPOR, as ERP self-interacts. ERP is specific for EPOR and associates noncovalently with EPOR in a ratio 1:1. Peptide binding to the receptor results in receptor-mediated cellular proliferation, intracellular signaling, and erythroid colony-forming unit formation in bone marrow cells. The activity is comparable to that of EPO. Recognition of such receptor sites represents a new and important concept in receptor function.

Applying a homology search method previously described, we identified a sequence in the extracellular dimerization site of the erythropoietin receptor, distant from the hormone binding site. A peptide identical to that sequence was synthesized. Remarkably, it activated receptor signaling in the absence of erythropoietin. Neither the peptide nor the hormone altered the affinity of the other for the receptor; thus, the peptide does not bind to the hormone binding site. The combined activation of signal transduction by hormone and peptide was strongly synergistic. In mice, the peptide acted like the hormone, protecting against the decrease in hematocrit caused by carboplatin.

Certain peptides derived from the alpha1 domain of the major histocompatibility class I antigen complex (MHC-I) inhibit receptor internalization, increasing the steady-state number of active receptors on the cell surface and thereby enhancing the sensitivity to hormones and other agonists. These peptides self-assemble, and they also bind to MHC-I at the same site from which they are derived, suggesting that they could bind to receptor sites with significant sequence similarity. Receptors affected by MHC-I peptides do, indeed, have such sequence similarity, as illustrated here by insulin receptor (IR) and insulin-like growth factor-1 receptor. A synthetic peptide with sequence identical to a certain extracellular receptor domain binds to that receptor in a ligand-dependent manner and inhibits receptor internalization. Moreover, each such peptide is selective for its cognate receptor. An antibody to the IR peptide not only binds to IR and competes with the peptide but also inhibits insulin-dependent internalization of IR. These observations, and binding studies with deletion mutants of IR, indicate that the sequence QILKELEESSF encoded by exon 10 plays a key role in IR internalization. Our results illustrate a principle for identifying receptor-specific sites of importance for receptor internalization, and for enhancing sensitivity to hormones and other agonists.

Initiation factor eIF2 binds GTP and promotes the binding of methionyl-tRNA to ribosomes. Biochemical and sequence evidence suggests that the GTP might bind to either the beta- or gamma-subunit of eIF2. Mutations were made in the NKXD consensus elements found in both subunits and individual mutant forms were overexpressed in transiently transfected COS-1 cells. The effect on the translational efficiency of a reporter mRNA for dihydrofolate reductase was monitored. Mutations in the gamma-subunit cause severe repression of protein synthesis, whereas those in the beta-subunit are only mildly inhibitory. The results support the view that GTP binds exclusively to the gamma-subunit.

Isoelectrofocusing gels of acidic ribosomal proteins from most yeast strains reveal the presence of up to 10 bands which are the product of only 4 genes. The proteins have been characterized by NH2-terminal amino acid sequencing, specific antibodies, HPLC, and by taking advantage of acidic protein-defective yeast strains obtained by gene disruption methods. The four most basic proteins coincide with the phosphorylated and dephosphorylated forms of the YP2 proteins, YP2 alpha and YP2 beta, formerly named L44 and L45. Amino-terminal sequencing has shown that these two polypeptides have free amino-terminal ends starting at the first methionine residue. The bands defined earlier as L44' correspond to the phosphorylated and dephosphorylated processed forms of protein YB1 beta lacking the first eight amino acids. The formation of this truncated YP1 beta form seems to be stimulated by salt during protein extraction and is also favored by some modifications at the amino termini of the protein. On the other hand, the previously uncharacterized band, called Ax, corresponds to an NH2-terminal acetylated form of YP1 beta which starts at the serine in the second position of the nucleotide-derived sequence. Finally, the most acidic band is the phosphorylated product of the fourth acidic protein gene. This protein, called YP1 alpha, which is very poorly stained by silver and Coomassie blue, has not been characterized in detail previously. It is also monophosphorylated in the ribosome and, like YP1 beta, is present as an NH2-terminal acetylated form starting at the second serine residue.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding of the yeast Tyr-tRNA and Phe-tRNA to the A site, and the binding of their acetyl derivatives to the P site of poly(U11,A)-programmed Escherichia coli ribosomes was studied. Spermine stimulated the rate of binding of both tRNAs at least threefold, enabling more than 90% final saturation of both ribosomal binding sites. The effect is observed when the tRNAs, but not ribosomes or poly(U11,A), are preincubated with polyamine. Regardless of the binding site, optimal saturation was reached at spermine/tRNA molar ratios of 3 for tRNA(Phe) and 5 for tRNA(Tyr). The same low spermine/tRNA ratios were previously reported to stabilize the conformation of these tRNAs in solution. On the other hand, the messenger-free, EF-Tu- and EF-G-dependent polymerization of lysine from E. coli Lys-tRNA is drastically reduced, while the poly(A)-directed polymerization is stimulated by spermine through a wide range of Mg2+ concentrations. Misreading of UUU codons as isoleucine, assayed by the A-site binding of E. coli Ile-tRNA, is also inhibited by spermine. All these results demonstrate that spermine increases the efficiency and accuracy of a series of macromolecular interactions leading to the correct incorporation of an amino acid into protein, at the same time preventing some unspecific or erroneous interactions. From the analogy with its known structural effects, it can be inferred that spermine does so by conferring on the tRNA a specific biologically functional conformation.