Thorpe Lab

oxidative protein folding

Immunohistochemistry of QSOX

There are two QSOX orthologs in humans: QSOX1 and QSOX2. These images refer to the distribution of QSOX1 in human tissues and represent the unpublished observations of Dr. Donald L. Coppock, Dr. George K. Turi and their coworkers. The photomicrographs have been graciously provided by Dr. Coppock. The panels utilize an antibody raised against a peptide from the second thioredoxin domain of QSOX1 (found in both QSOX1a and QSOX1b isoforms [PubMed]).  Tissues were fixed with formalin, the brown-to-puce stain is diaminobenzimide, and the counter stain is hematoxylin.

 

web-1-A1_Insulinoma_Control_Q6_CD4-33
web-1-B1_Placenta_control_Q6_CD4-19
web-1-C1_Thyroid_CD_4-22
web-1-C2_Parathyroid_CD_5-32
web-1-C3_Pituitary_CD4
web-1-C4_Testes_Leydig_Cells_CD3-27
web-1-D1_Pancreas_Islet_CD1-29
web-1-D2_Pancreatic_islet_detail_CD_4-36
web-1-D3_Insulinoma_CD4-40
web-1-D4_Pancreatic_duct_with_detail_of_NE_cell_CD_4-38
web-1-E1_Prostate_epithelium_CD3-50
web-1-E2_Submandibular_Seromucinous_Gland_CD5-3
web-1-E3_Parotid_CD4-9
web-1-E4_Parotid_(coronal_view)
web-1-F1_Breast_Cross_section_of_Duct_Najma_Scope
web-1-F1_Breast_Normal_Duct
web-1-F2_Breast_Lobular_Unit_Najma_Scope
web-1-F2_Breast_normal_lobule
web-1-F3_Breast_Apocrine_Metaplasia_CD4-41
web-1-F4_Breast_Lobular_CA_CD4-47
web-2-A1_Breast_Invasive_Ductal_CA
web-2-A2_BRCA_cribiform_intraductal_carcinoma
web-2-A3_Endometrium_secretory
web-2-A4_Secretory_Endometrium
web-2-B1_Luteinized_Corpus_Leuteum_CD4-70
web-2-B2_Follicular_Cyst
web-2-B3_Early_Placenta
web-2-B4_Decidualized_Placenta
web-2-C1_Small_intestine
web-2-C2_Small_intestine_with_Neuro_endocrine_cells
web-2-C3_Small_intestine_crypt
web-2-C4_Brunner
web-2-D1_Stomach_final
web-2-D2_Nerve_in_colon_CD4-51
web-2-D3_Kidney_Glomerulus
web-2-D4_Kidney_Medulla_with_TH_protein
web-2-E1_Skin_Epidermis_Najma_Scope
web-2-E2_Sebaceous_Gland
web-2-E3_Hair_Follicle_Cross_Section
web-2-E4_Skin_Apocrine_gland
web-2-F1_Skin_Eccrine_gland
web-2-F2_Skin_epithelial_carcinoma_of_the_vulva
web-2-F3_Liver_with_kupfer_cell
web-2-F4_Lung_Epidermis_and_Gland
web-2-G1_Hematopoeitic_Plasma_Cells_and_Lymphocytes_in_Seromucinous_gland
web-2-G2_Hematopoeitic_Bone_Marrow
web-2-G3_Lymphoid_Follicle_in_Tonsil
web-2-G4_H929_Cells
01/48 
start stop bwd fwd

 

QSOX-ology

The term "sulfhydryl oxidase" was introduced more than 50 years ago to describe an activity characterized from mammalian skin that catalyzed the reaction:

2 RSH + O2 → RS-SR + H2O2

Later, enzymes from milk (1967) and seminal vesicles (1979) were found to catalyze the same reaction. Eventually all three oxidases were recognized to be members of what is now know as the Quiescin-sulfhydryl oxidase (QSOX) family of flavin-linked oxidases. QSOXs are found in most eukaroyotes - from the smallest free-living eukaryote (Ostreococcus tauri) to humans. QSOXs are absent in the fungi. The evolutionarily unrelated Ero1 flavoprotein sulfhydryl oxidases have been found in all eukaryotes so far examined .

A chronology of some key events in the characterization of the flavin-linked sulfhydryl oxidases (together with other key developments in oxidative protein folding) is presented below.

Read more...

You are here: Home QSOX-ology