Disease relevance of PF3

• A cytotoxic T lymphocyte epitope of the CS protein of P. falciparum, PF3, recognized by CD8+ T cells of H-2(k) mice, was expressed in a re vaccinia virus (VacPf) and a re influenza virus (FluPf) [1].
• In addition to podoviruses T3 and T7, strand bias of recognition sequences for different type III DNA modification-restriction enzymes is also observed in the inoviruses M13, IKE and PF3 [2].
• Thrombocytopenia was observed in 10 cases (33.3 percent), reduced availability of PF3 in 8 cases (26.6 percent), multiple coagulation factor defects in 18 cases (60 percent), increased euglobulin lysis activity in 8 cases (26.6 percent) and low plasma fibrinogen in 12 cases (40 percent) [3].
• The patients with myasthenia gravis also showed a considerable frequency (20%) of platelet antibodies detectable by the PF3 test [4].
• The CsC1 equilibrium centrifugation patterns reveal low figures for phage PF1, PF2 and PF3 and show off the fact that PF4 lysates contain two viral particules different with respect to their densities, a property which other determinations failed to demonstrate [5].

High impact information on PF3

• VacPf also greatly enhanced the primary response of mice injected with P. falciparum sporozoites or with a lipopeptide containing PF3 [1].
• Group 3 antibodies (PF3/A, an IgG1; PF3/B, an IgGM; and PF3/C, an IgG2a) react additionally with certain other tumors, as well as with normal adult and fetal epidermis [6].
• Aggregates of PF3 are described which provided insight into the assembly and macromolecular structure of fibrillin in microfibrils [7].
• In this theoretical study on rhodium-catalysed hydroformylation we examine an unmodified hydridorhodium(I) carbonyl system a together with three variants modified by the model phosphane ligands PF3 (system b), PH3 (system c) and PMe3 (system d), which show increasing basicity on the Tolman chi parameter scale [8].
• The first tris(arene)niobium complex, [Nb(1-4-eta 4-anthracene)3]-, has been obtained by the sodium or potassium anthracene reduction of NbCl4(THF)2, structurally characterized by X-ray analysis and shown to undergo facile anthracene displacement reactions in the presence of excess CO, PF3, 1,3,5,7-cyclooctatetraene and P(OMe)3 [9].

Biological context of PF3

• 1. The mechanisms underlying the muscle relaxation effect of a fraction (PF3) isolated from the Phoneutria nigriventer spider venom were assessed on mouse diaphragm and chick biventer cervicis muscle preparations [10].
• 2. PF3 (0.25-4 micrograms ml-1) produced a concentration-dependent blockade of the nerve-elicited muscle twitch of the mouse diaphragm (IC50 = 0.8 micrograms ml-1) without affecting the directly induced muscle twitch [10].
• In terms of ORFs, gpflp-1 was 444 base pairs (bp) long and coded for four copies of the FaRP, PF3 (KSAYMRFamide) whilst gpflp-2 was 309 bp long and encoded one copy of the peptide, KNKFEFIRFamide. gpflp-3 (420 bp) Encoded two copies of KHEYLRFamide (AF2) and the genes gpflp-4 and gpflp-5 encoded a total of 11 FaRPs, most of which are novel to PCN [11].
• Finally, we examined the effects of inhibitors on the appearance of PF1, PF3, platelet factor 4, total intrinsic factor V activity, and serotonin as well as on platelet aggregation [12].
• This PCA is shown to be fully reversible, with morphologic reversion of shape-changed platelets to the discoid form, and is shown to be distinct from other PCAs previously described for platelets activated in different ways, such as PF3 activity [13].

Anatomical context of PF3

• 4. PF3 (2-8 micrograms ml-1) reduced the frequency of miniature endplate potentials (m.e.p.ps) recorded intracellularly from the mouse diaphragm muscle fibers by 58 to 64%, and diminished the amplitude of m.e.p.ps by 20 to 40% of control [10].
• However, under the influence of DC-T from Peyer's patches PF1C secreted predominantly IgM, PF1 secreted primarily IgA, and a third line, PF3, secreted primarily IgG [14].
• Letter: Microtubule reorganization in platelets may express PF3 activity [15].
• 3.2 Consumptive coagulopathy due to the activation by mononuclear phagocytes, PF3 released from platelet aggregation [16].
• Formation of the platelet thromboplastic activity, so called PF3, is linked to the platelet storage organelles disintegration and lypolysis during their exocytosis through the platelet plasma membrane [17].

Associations of PF3 with other chemical compounds

• Ascaris suum contains a large number of FMRFamide-related peptides (FaRPs) of which KNEFIRFamide (AF1), KHEYLRFamide (AF2) and KSAYMRFamide (AF8, also called PF3) have been extensively studied and are known to exert actions on somatic muscle strips of the worm [18].
• The decrease of PF3 and PF4 availability in these cases was comparable to the results of the first group [19].
• In order to exclude a longer latency time for the diminution of PF3 and pf4 availability, a second series of ten patients received intravenous injections of 100 and 300 mg ASA, respectively [19].
• Measurements have been taken from capillary beds and single larger vessels over a range of temperatures and from avascular yolk and egg white using a Perimed PF3 with PF310 bent-tipped probe [20].
• The tests performed included bleeding time (BT), platelet count, prothrombin time (PT), prothrombin consumption index (PCI), activated partial thromboplastin time (APTT), PF3 release with adenosine diphosphate (ADP) at 0 and 20 min, total PF3 assay and platelet Aggregation studies with collagen, ADP, adrenaline, arachidonic acid and ristocetin [21].

Gene context of PF3

• A new flp-gene, designated flp-6, has recently been identified which encodes six copies of KSAYMRFamide (PF3/AF8) [22].
• After sedimentation of stimulated platelets, 31% of total PF1 and 41% of PF3 remained in the supernatant fraction [12].
• One of these fractions, PF3, was chemically characterized as a cysteine-rich polypeptide of approximately 8360 MW [23].
• Growing rats were fed for 14 days a protein-free diet containing PVE at a nutritional concentration of 0% (PF1), 0.4% (PF2), or 1.1% PVE (PF3) or 1.1% autoclaved PVE (PF4) [24].
• Subjects with a history of generalized bleeding and a prolonged bleeding time, PF3 availability or prothrombin consumption index and a normal platelet count, prothrombin time, activated partial thromboplastin time and clot solubility were subjected to platelet aggregation [25].

Analytical, diagnostic and therapeutic context of PF3

• Upon centrifugation of the void volume fractions, PF1 and PF3 activities, phosphate-containing material, and ultraviolet-absorbing material all sedimented at the same rate, indicating that PF1 and PF3 are activities associated with one or both of the platelet-derived vesicle populations [12].
• Partial sequence analysis of PF3 revealed certain homologies with other spider toxins already described, particularly omega-AGAIIA (60%) from Agelenopsis aperta [23].
• Among the cases of CLL and CLL related disorders, bleeding time was prolonged in two, clot retraction was impaired in one and PF3 availability was decreased in three cases [26].
• During hemodialysis the decrease of other platelet functions such as adhesiveness, aggregation induced by ADP, collagen and PF3 remained unchanged [27].

References