ジャーナル: Nat Commun / 年: 2022 タイトル: Structure of the proteolytic enzyme PAPP-A with the endogenous inhibitor stanniocalcin-2 reveals its inhibitory mechanism. 著者: Sara Dam Kobberø / Michael Gajhede / Osman Asghar Mirza / Søren Kløverpris / Troels Rønn Kjær / Jakob Hauge Mikkelsen / Thomas Boesen / Claus Oxvig / 要旨: The metzincin metalloproteinase PAPP-A plays a key role in the regulation of insulin-like growth factor (IGF) signaling by specific cleavage of inhibitory IGF binding proteins (IGFBPs). Using single- ...The metzincin metalloproteinase PAPP-A plays a key role in the regulation of insulin-like growth factor (IGF) signaling by specific cleavage of inhibitory IGF binding proteins (IGFBPs). Using single-particle cryo-electron microscopy (cryo-EM), we here report the structure of PAPP-A in complex with its endogenous inhibitor, stanniocalcin-2 (STC2), neither of which have been reported before. The highest resolution (3.1 Å) was obtained for the STC2 subunit and the N-terminal approximately 1000 residues of the PAPP-A subunit. The 500 kDa 2:2 PAPP-A·STC2 complex is a flexible multidomain ensemble with numerous interdomain contacts. In particular, a specific disulfide bond between the subunits of STC2 and PAPP-A prevents dissociation, and interactions between STC2 and a module located in the very C-terminal end of the PAPP-A subunit prevent binding of its main substrate, IGFBP-4. While devoid of activity towards IGFBP-4, the active site cleft of the catalytic domain is accessible in the inhibited PAPP-A·STC2 complex, as shown by its ability to hydrolyze a synthetic peptide derived from IGFBP-4. Relevant to multiple human pathologies, this unusual mechanism of proteolytic inhibition may support the development of specific pharmaceutical agents, by which IGF signaling can be indirectly modulated.
分子量: 40.078 Da / 分子数: 16 / 由来タイプ: 合成 / 式: Ca / タイプ: SUBJECT OF INVESTIGATION
研究の焦点であるリガンドがあるか
Y
Has protein modification
Y
-
実験情報
-
実験
実験
手法: 電子顕微鏡法
EM実験
試料の集合状態: PARTICLE / 3次元再構成法: 単粒子再構成法
-
試料調製
構成要素
ID
名称
タイプ
詳細
Entity ID
Parent-ID
由来
1
PAPP-A dimer in complex with its endogenous inhibitor STC2 dimer
COMPLEX
Inhibited proteolytic complex generated by harvest of serum media, purifying on a nickel column followed by negative affinity purification and size-exclusion chromatography.
#1-#2
0
RECOMBINANT
2
Pregnancy-associated plasma protein A
COMPLEX
Homodimer
#2
1
RECOMBINANT
3
Stanniocalcin-2
COMPLEX
Homodimer
#1
1
RECOMBINANT
分子量
ID
Entity assembly-ID
値 (°)
実験値
1
1
0.5MDa
YES
2
1
0.4MDa
YES
3
1
0.1MDa
YES
由来(天然)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
細胞内の位置
組織
2
1
Homo sapiens (ヒト)
9606
extracellular
ubiquitous
3
2
Homo sapiens (ヒト)
9606
extracellular
ubiquitous
4
3
Homo sapiens (ヒト)
9606
extracellular
ubiquitous
由来(組換発現)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
細胞
プラスミド
2
1
Homo sapiens (ヒト)
9606
embryonickidneycells
pcDNA
3
2
Homo sapiens (ヒト)
9606
embryonickidneycells
pcDNA
4
3
Homo sapiens (ヒト)
9606
embryonickidneycells
pcDNA
緩衝液
pH: 7.4 詳細: HEPES buffer 20 mM Hepes pH 7.5 100 mM NaCl, 1mM CaCl
緩衝液成分
ID
濃度
名称
式
Buffer-ID
1
20mM
Hepes
Hepes
1
2
100mM
NaCl
NaCl
1
3
1mM
CaCl
CaCl
1
試料
濃度: 0.6 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES