Synthesis of Casein Related Peptides and Phosphopeptides. XIV. Solid Phase Synthesis of Glu-Ser(P)-Leu Through the Use of Protected Boc-Ser(PO3R2)-OH Derivatives

1991 ◽  
Vol 44 (6) ◽  
pp. 771 ◽  
Author(s):  
JW Perich ◽  
RM Valerio ◽  
PF Alewood ◽  
RB Johns

A solid phase method is described for the synthesis of O- phosphoseryl-containing peptides by the use of polystyrene resin (Merrifield) as the peptide support and protected Boc-Ser(PO3R2)-OH derivatives for the incorporation of the phosphorylated seryl residue. The viability of this solid phase approach was demonstrated by the synthesis of HBr.H-Glu-Ser (PO3Et2)-Leu-OH in high yield by the use of Bo -Ser(PO3Et2)-OH in peptide synthesis and subsequent use of HBr/CF3CO2H for cleavage of the Ser(PO3Et2)-containing tripeptide from the resin support. Similarly, the dipeptide, CF3CO2H.H-Ser(P)- Leu -OH, was prepared in high yield by using Boc -Ser(PO3But2)-OH in peptide synthesis followed by the one-step deprotection of the Ser(PO3But2)- dipeptide resin by treatment with HBr/CF3CO2H (90 min). Alternatively, the O-phosphoseryl tripeptide , CF3CO2H.H-Glu-Ser(P)- Leu -OH was prepared by using either Ppoc -Ser(PO3Bzl2)-OH or Boc-Ser(PO3Ph2)-OH in peptide synthesis. The one-step deprotection of the Ser(PO3Bzl2)-containing tripeptide and cleavage of the peptide from the resin support was effected by high-pressure hydrogenolysis (palladium acetate). In the case of phenyl phosphate protection, the Ser(PO3Ph2)-containing peptide was cleaved from the resin support by high-pressure hydrogenolysis (palladium acetate) followed by cleavage of the phenyl phosphate groups by platinum-mediated hydrogenolysis (1.0 equiv. PtO2/phenyl group) in 50% CF3CO2H/AcOH.

1972 ◽  
Vol 50 (7) ◽  
pp. 755-757 ◽  
Author(s):  
W. K. Park ◽  
D. Regoli

The vessel for the synthesis of peptides by the solid-phase method consists of a round flask with one side-arm and three stopcocks. The side-arm is used to attach the vessel to a wrist-shaker and to insert a gas dispersion tube for the cleavage of the synthesized peptide. Solvents and reagents are introduced from the stopcock on the top and removed from the one at the bottom, by applying negative pressure and by opening the lateral stopcock at the same time.


Author(s):  
Gregory A. Grant

In 1987, an article appeared in the International Journal of Peptide and Protein Research commemorating the 25th anniversary of the development of solid phase peptide synthesis (Barany et al., 1987). While that article dealt with many aspects of peptide synthesis, one statement in particular stands out as exemplifying the rationale for this chapter. It states: “No synthetic endeavor can be considered complete until the product has been adequately purified and subjected to a battery of analytical tests to verify its structure.” The characterization or evaluation of a synthetic peptide is the one step in its production and experimental utilization that will validate the experimental data obtained. Unfortunately, it is also the one step that many investigators all too often give too little attention. If the synthetic product, upon which the theory and performance of the experimental investigation is based, is not the intended product, the conclusions will be incorrect. Without proper characterization, the investigator will either have to be lucky, or be wrong. Worse yet, he or she will not know which is the case. Although today the synthesis of a given peptide is often considered routine, the product should never be taken for granted. Peptide synthesis chemistry, although quite sophisticated, is complex and subject to a variety of problems. These problems, which can manifest themselves as unwanted side reactions and decreased reaction efficiency, are subject to a variety of factors such as reagent quality, incompatible chemistries, instrument malfunctions, sequence specific effects, and operator error. Although every effort is made to eliminate their causes and to plan for potential problems in the design and synthesis steps, it is not always successful and the eventual outcome of a synthesis is not always predictable. One must never assume that the final product is the expected one until that has been proven to be the case. To do otherwise may seriously jeopardize the outcome of the research. Used and performed properly, the evaluation stage is where the fruits of the synthesis are scrutinized and the decision is made to use the peptide as intended, submit it to further purification, or resynthesize it and possibly change elements of the design or synthesis protocols.


1991 ◽  
Vol 56 (2) ◽  
pp. 491-498 ◽  
Author(s):  
Bernard Lammek ◽  
Izabela Derdowska ◽  
Tomasz M. Wierzba ◽  
Witold Juzwa

In an attempt to determine some of the structural features in position 1 that account for V1 antagonism, four new analogues of arginine-vasopressin were synthesized and the effect of the modifications on the vasoconstrictor activity was checked using isolated mesenteric arterial vessels of rats. The protected precursors required for these analogues were synthesized by a solid phase method of peptide synthesis. One of the reported analogues, namely [1-(4-mercapto-4-tetrahydrothiopyraneacetic acid)., 2-O-methyltyrosine, 8-arginine]vasopressin appears to be a potent competitive antagonist of the vasoconstrictor effect by AVP.


2021 ◽  
Vol 858 ◽  
pp. 158344
Author(s):  
Xuecheng Cai ◽  
Shuaijun Ding ◽  
Zhongjie Li ◽  
Xin Zhang ◽  
Kangkang Wen ◽  
...  

2021 ◽  
Vol 60 (01) ◽  
pp. 38-46
Author(s):  
Johannes J. Roggenbuck ◽  
Grit Zarske ◽  
Peter Schierack ◽  
Gerd Wunderlich ◽  
Karsten Conrad ◽  
...  

Abstract Aim TSH-receptor (TSHR)-autoantibody (TRAb) is the serological hallmark of Graves’ disease (GD). Recently, 3rd-generation radioimmunoassays (RIA) employing monoclonal TRAb such as M22 or T7 instead of TSH for the inhibition of human TRAb binding with solid-phase TSHR (coated tubes) have been introduced into laboratory routine. Methods As current assays typically employ a consecutive incubation of patient serum and labelled monoclonal TRAb, automation of TRAb RIA is a challenge. Thus, the assay procedure using human TSHR-coated tubes and the mouse monoclonal TRAb T7 was modified by combining both steps. The novel one-step method was compared with its corresponding consecutive 3rd-generation RIA by investigating 304 individuals encompassing 102 patients with active GD (GDa), 43 patients with GD after successful therapy (GDt), 31 with Hashimoto’s disease (HD), 28 with non-autoimmune thyroid diseases (NAITD) and 100 healthy subjects (HS). Results With the new method, the incubation time was shortened by approximately one hour. Both 3rd-generation RIAs did not reveal a significantly different assay performance by comparing areas under the curve (AUC) with receiver operating characteristics curve analysis (AUC one-step: 0.94, AUC two-step: 0.96, p > 0.05, respectively). The two-step TRAb RIA demonstrated sensitivity and specificity values of 87.5 % and 96.2 %, respectively, whereas the one-step revealed 84.6 % and 96.2 %, respectively. Conclusion One-step 3rd-generation RIA may be used for the reliable detection of TRAb. The shorter and easier assay design may improve its use and enable automation in routine nuclear medicine laboratories.


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