Protein factors

Parallel to the activities in the treatment of pernicious anemia were observations in the 1930s that most farm animals had a requirement for an unknown factor beyond the vitamins then known. The lack of this factor became apparent, eg, when chicks or pigs fed a diet with only vegetable protein evidenced slow growth rate and high mortahty. It became apparent that the requited factor, termed animal protein factor, was present in animal sources such as meat and tissue extracts, milk whey, and cow manure. Subsequent to its isolation, it was rapidly shown that vitamin B 2 is the same as animal protein factor. 

Transcription exhibits three phases initiation, elongation, and termination. All are dependent upon distinct DNA czV-elements and can be modulated by distinct tranS jzim protein factors. 

This drug is more potent and more selective for fibrin-bound plasminogen than any other known plasminogen activator. Unlike t-PA, desmoteplase is not activated by fibrinogen or (3-amyloid proteins, factors that may exacerbate the risk for ICH. Moreover, desmoteplase inhibits t-PA-induced potentiation of excitotoxic injury. The effect of IV administration of desmoteplase 3-9 hours after symptom onset in stroke patients who demonstrate a mismatch on PWI/DWI MRI is currently being investigated. ... 

Compound 508 (PNRI-299), a small molecule /3-strand mimetic template compound, is active as an inhibitor of the multifunctional activating protein factor 1 (AP-1). PNRI-299 has demonstrable effects on the reduction of API-driven transcription and beneficial pharmacological effects in a mouse asthma model. The compound affects the expression of leukotriene C4 (LTC4) synthase, a crucial enzyme for the formation of the cysteinyl leukotrienes <2003PNA1169, 2004MI211>. 

HELMINGER, J., RAUSCH, T HILGENBERG, W., A soluble protein factor from Chinese cabbage converts indole-3-acetaldoxime to IAA, Phytochemistry, 1987, 26, 615-618. 

The protein factor in MetaSite is based on homology models of the CYP450s, but it offers the possibility for the user to introduce any CYP450 structure. Several analyses have been done comparing the results obtained using the crystal structures and the homology models of the cytochromes. 

Figure 1. Hierarchical model of chromosome structure, (a) In interphase cells, DNA is packed in a nucleus as forming nucleosome and chromatin, (b) DNA forms nucleosome structure together with core histone octamer, which is then folded up into 30nm fiber with a help of linker histone HI. This 30 nm fiber is further folded into 80 nm fiber and 300 nm loop structures in a nucleus. In mitosis, chromosome is highly condensed. Proteins which are involved in each folding step are indicated above and non-protein factors are indicated below, (c) The amino acid sequences of histone tails (H2A, H2B, H3 and H4) are shown to indicate acetylation, methylation and phosphorylation sites. (See Colour Plate 1.)...

RF3)" " with the ribosome. However, the maximum resolution that can currently be obtained by cryo-EM is about 10 nm (8-12 A), far from the desired atomic resolution. Therefore, the crystal structures of the 30S subunit with initiation factors 1 and 3 (IFl IF3 ) and of the 70S subunit with release factors 1 and 2 (RFl/2 " ) as well as RRF have been important milestones toward understanding the interaction of the ribosome with protein factors. 

There is a single prokaryotic RNA polymerase that synthesizes all types of RNA in the cell. The core polymerase responsible for making the RNA molecule has the subunit structure Ojpp. A protein factor called sigma (a) is required for the initiation of transcription at a promoter. Sigma factor is released immediately after initiation of transcription. Termination of transcription sometimes requires a protein called rho (p) faaor. This enzyme is inhibited by rifampin. Actinomycin D binds to the DNA preventing transcription. 

Answer C. eIF-2 designates a protein factor of the initiation phase in eukaryotic translation. The only event listed that would occur during this phase is placement of initiator tRNA in the P-site. 

Produce recombinant proteins (Factor VIII, FIBsAg, insulin)... 

The era of feed additive antibiotics had its beginning in the late 1940 s in a classic example of serendipity. Investigators at the Lederle Laboratories were searching for a more convenient source of "animal protein factor", a substance found in liver and other animal proteins that stimulated the growth of chicks fed a vegetable diet (1). [It had already been demonstrated by workers... 

Normally, thrombin is present in the blood as an inactive proenzyme (see p. 270). Prothrombin is activated in two different ways, both of which represent cascades of enzymatic reactions in which inactive proenzymes (zymogens, symbol circle) are proteolytically converted into active proteinases (symbol sector of a circle). The proteinases activate the next proenzyme in turn, and so on. Several steps in the cascade require additional protein factors (factors 111, Va and Villa) as well as anionic phospholipids (PL see below) and Ca "" ions. Both pathways are activated by injuries to the vessel wall. 

Any DNA sequence that binds protein factors and thereby stimulates transcription. This stimulatory effect may occur over an appreciable distance from the enhancer s site. Enhancers act in either strand orientation, and they can be found either upstream or downstream with respect to the promoter. 

Intrinsic pathway All the protein factors necessary for coagulation are present in circulating blood. Clot formation may take several minutes and is initiated by activation of factor XII. 

Lescure, A., Fagegaltier, D., Carbon, P. and Krol, A. (2002). Protein factors mediating selenoprotein synthesis. Curr. Protein Pept. Sci. 3,143-151. 

---