[A deletion mutant of plasminogen kringle 5 inhibits retinal capillary endothelial cell proliferation].
OBJECTIVE
To obtain purified deletion mutant of plasminogen kringle 5 (K5) using gene mutation and genetic recombination methods and assess its anti-angiogenic activity in vitro.


METHODS
A deletion mutant of K5 was obtained by deleting 15 amino acids from K5 while retaining all the 3 disulfide bonds. This K5 mutant (Mut1) was expressed in E. coli and affinity purified. The inhibition effect of K5 Mut1 on primary retinal capillary endothelial cells and pericytes from the same origin was assessed by MTT assay.


RESULTS
The K5 Mut1 inhibited the proliferation of primary retinal capillary endothelial cells in a concentration-dependent manner, with an apparent half-inhibition concentration (EC(50)) of approximately 35 nmol/L, which was 2-fold more potent than intact K5. In the same concentration range, this peptide did not inhibit pericytes from the same origin, suggesting an endothelial cell-specific inhibition.


CONCLUSIONS
This K5 deletion mutant is a more potent angiogenic inhibitor than K5 and may have therapeutic potential in the treatment of such disorders with abnormal neovascularization as diabetic retinopathy, age-related macular degeneration and solid tumor.
Ma
Jian-fang
JF
476 Hospital of PLA, Fuzhou 350002, China.
Yang
Zhong-han
ZH
Li
Chao-yang
CY
Cai
Wei-bin
WB
Song
Zhi-hong
ZH
Guo
Yin
Y
Guo
Lin-lang
LL
Li
Min-you
MY
Liu
Zhu-guo
ZG
Gao
Guo-quan
GQ
D000818:Animals; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology; D017353:Gene Deletion; D018082:Kringles / Q000502:physiology*; D010958:Plasminogen / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000494:pharmacology; D012171:Retinal Vessels / Q000166:cytology / Q000187:drug effects*
D011994:Recombinant Proteins; D010958:Plasminogen