Ala657and Conserved Active Site Residues Promote Fibroblast Activation Protein Endopeptidase Activity via Distinct Mechanisms of Transition State Stabilization

Biochemistry ◽  
2007 ◽  
Vol 46 (15) ◽  
pp. 4598-4605 ◽  
Author(s):  
Sarah A. Meadows ◽  
Conrad Yap Edosada ◽  
Mark Mayeda ◽  
Thuy Tran ◽  
Clifford Quan ◽  
...  
Keyword(s):  
Transition State ◽  
Active Site ◽  
Fibroblast Activation Protein ◽  
Active Site Residues ◽  
Fibroblast Activation ◽  
Transition State Stabilization ◽  
Endopeptidase Activity

Functional tyrosine residue in the active center of human dipeptidyl peptidase III

2008 ◽  
Vol 389 (2) ◽  
pp. 163-167 ◽  
Author(s):  
Branka Salopek-Sondi ◽  
Bojana Vukelić ◽  
Jasminka Špoljarić ◽  
Šumski Šimaga ◽  
Dušica Vujaklija ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transition State ◽  
Active Site ◽  
Functional Role ◽  
Dipeptidyl Peptidase ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Tyrosine Residue ◽  
Transition State Stabilization ◽  
Endogenous Defense

Abstract Human dipeptidyl peptidase III (DPP III) is a member of the metallopeptidase family M49 with an implied role in the pain-modulatory system and endogenous defense against oxidative stress. Here, we report the heterologous expression of human DPP III and the site-directed mutagenesis results which demonstrate a functional role for Tyr318 at the active site of this enzyme. The substitution of Tyr318 to Phe decreased k cat by two orders of magnitude without altering the binding affinity of substrate, or of a competitive hydroxamate inhibitor designed to interact with S1 and S2 subsites. The results indicate that the conserved tyrosine could be involved in transition state stabilization during the catalytic action of M49 peptidases.

scholarly journals Visualization of the Differential Transition State Stabilization within the Active Site Environment

2004 ◽  
Vol 5 (4) ◽  
pp. 186-195 ◽  
Author(s):  
Pawel Kedzierski ◽  
Pawel Wielgus ◽  
Adrian Sikora ◽  
W. Sokalski ◽  
Jerzy Leszczynski
Keyword(s):  
Transition State ◽  
Active Site ◽  
Transition State Stabilization

Effect of short hairpin RNA targeting of fibroblast activation protein on tumor growth and angiogenesis in a 4T1 murine breast cancer model.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13538-e13538
Author(s):  
Fan Cai ◽  
Feng Peng ◽  
Chunting Wang ◽  
Zhiyong Li ◽  
Shuang Xian ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Fibroblast Activation Protein ◽  
Cancer Growth ◽  
Control Groups ◽  
Fibroblast Activation ◽  
Epithelial Cancers ◽  
Endopeptidase Activity ◽  
Proteolytic Activities ◽  
4T1 Breast Cancer ◽  
Breast Cancer Growth

e13538 Background: Fibroblast activation protein(FAP) is an increased abnormal signal protein in the TME and has  both dipeptidyl peptidase and endopeptidase activity. FAP has been recognized to influence cancer growth and invasion, through its non- enzyme function or proteolytic activities in concert with other moleculars such as CD26, uPAR, β1-integrin, and MMP-1. Since FAP is over expression in epithelial cancers and absent from normal adult tissues, it has long been suggested to be a target of antitumor therapy. Methods: 21 BALB/C female mice implanted with 4T1 breast cancer were enrolled and randomly divided into three groups (n=7 per group) .The experiment group(E-group) was administered with shRNA targeting of FAP every 48 hours in 2 weeks by local administration, and the two control groups with HK or 5%GS. Tumor volumes and weights were monitored. Expression of FAP was detected by RT-PCR and immunohistochemistry staining. Collagen fiber, microvessel density and cell apoptosis were investigated. Results: The expression of FAP was reduced about 50% by shRNA targeting of FAP; the tumor volume and weight of the E-group showed significant reduction of 40% compared with the controls (p=0.001). Knockdown of FAP increased accumulation of disorganized collagen fibers; the MVD in control groups was about 4 times at least compared to the E-group (p<0.001) and apoptosis cells markedly increased 3 fold (p=0.0015). Conclusions: Knockdown of FAP by shRNA interference mediated inhibition of breast cancer growth, amelioration of the tumor microenvironment including increased accumulation of disorganized collagen, suppressed angiogenesis, and promotion of apoptosis. FAP contributes to the formation of TME and is a stimulative factor of breast cancer growth. Target of FAP may be a potential supplemental therapeutic method for breast cancer.

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