Ribosomally synthesized and post-translationally modified peptides (RiPPs) constitute a vast and diverse family of bioactive peptides. These peptides, synthesized by ribosomes and subsequently modified by various tailoring enzymes, possess a wide chemical space. Among these modifications, radical S-adenosylmethionine (rSAM) enzymes employ unique radical chemistry to introduce a variety of novel peptide structures, which are crucial for their activity. This review examines the major types of modifications in RiPPs catalyzed by rSAM enzymes, incorporating recent advancements in protein structure analysis techniques and computational methods. Additionally, it elucidates the diverse catalytic mechanisms and substrate selectivity of these enzymes through an analysis of the latest crystal structures.
Protein Processing, Post-Translational ; S-Adenosylmethionine/chemistry* ; Ribosomes/metabolism* ; Peptides/metabolism* ; Biological Products/metabolism* ; Humans

Protein S deficiency causing arterial ischemic stroke during pregnancy is uncommon. Delay or omission of treatment with perfusion therapies may worsen outcomes for both the mother and the fetus. In this paper, we report a case of an early pregnant woman with protein S deficiency and multiple history of chronic cerebrovascular disease who underwent successful thrombolysis and mechanical thrombectomy. The patient is a 35-year-old woman, eight weeks pregnant, with a history of protein S deficiency and chronic cerebrovascular disease, presenting with rightsided weakness and aphasia. Initial National Institutes of Health Stroke Scale was 10 with cranial magnetic resonance imaging findings of acute infarcts on the left caudate, lentiform nucleus, insula, and frontal lobe with a large vessel occlusion on the proximal M1 segment of the left middle cerebral artery. Intravenous thrombolysis and mechanical thrombectomy were performed with complete recanalization. The patient improved and delivered without any complications after 8 months. Protein S deficiency can contribute to arterial thrombosis including ischemic stroke. Arterial ischemic stroke and large vessel occlusion can cause significant disability if not treated appropriately. Reperfusion therapies in pregnant women show favorable outcomes and should be performed if the benefits outweigh the risks.

Hereditary protein S deficiency (PSD) is an autosomal dominant disorder caused by mutations in the PROS1 gene which can cause venous thrombosis. Individuals with PSD usually present with recurrent deep vein thrombosis and/or pulmonary embolism, but thrombosis may occur at unusual sites, such as the mesenteric and portal veins. Here we report a case of hereditary protein S deficiency patient with predominant mesenteric venous thrombosis. A 57-year-old man was admitted for abdominal pain and bilateral lower limber swelling. His sister had a history of thrombotic disease. On admission, His temperature was 37.4 ℃, the pulse was regular, and the blood pressure was 130/79 mmHg. Abdominal examination showed right lower abdomen tenderness, rebound tenderness and suspected muscle rigidity. Abdominal computed tomography (CT) angiography found that the patient had superior mesenteric venous thrombosis (MVT) and perforation of intestine. Vascular ultrasound of lower limb indicated bilateral deep venous thrombosis. Although treatment of fasting, water restriction, parenteral nutrition solution, acid suppression, anti-biotic treatment and low molecular weight heparin for anticoagulation were given, abdominal pain were not relieved. Small intestine resection and anastomosis was done after. Pathology of intestine did not show changes indicative of vasculitis. To investigate the cause of multiple thrombosis, a work-up for hypercoagulability (protein C and S activities, antithrombin, lupus anticoagulant, anti-cardiolipin antibody, anti-β2 glycoprotein Ⅰ antibody) was done and the result showed increased dRVVT ratio and the significantly decreased protein S levels. Anti-phospholipid syndrome (APS) was suspected because of the thrombosis and positive lupus anticoagulant, but at the time of the test the patient was on oral anticoagulants which might influence the result of lupus anticoagulant. The lupus anticoagulant was normal after discontinuing oral anticoagulants and APS was excluded. Because of his personal and family history of thrombotic disease, a hereditary thrombophilia was suspected and a laboratory analysis showed a reduced protein S activity. Further examination of the whole exome sequencing indicated a heterozygous mutation in the PROS1 gene. He was diagnosed with hereditary protein S deficiency and was started on anticoagulant therapy with rivaroxaban. He had been followed up for 1 year, and his condition kept stable without newly developed thrombosis or bleeding.
Humans ; Male ; Protein S Deficiency/genetics* ; Middle Aged ; Venous Thrombosis/etiology* ; Mesenteric Veins ; Protein S/genetics* ; Mutation ; Abdominal Pain/etiology*

Reduced protein S activity is one of the high-risk factors for venous thromboembolism.Hereditary protein S deficiency is an autosomal dominant disorder caused by mutations in the PROS1 gene.We reported a female patient with a mutation of c.292 G>T in exon 3 of the PROS1 gene,which was identified by sequencing.The genealogical analysis revealed that the mutation probably originated from the patient's mother.After searching against the PROS1 gene mutation database and the relevant literature,we confirmed that this mutation was reported for the first time internationally.
Humans ; Female ; Protein S/genetics* ; Protein S Deficiency/genetics* ; Pedigree ; Mutation

Objective: To analyze the clinical manifestations and molecular pathogenesis of 18 patients with inherited protein S (PS) deficiency. Methods: Eighteen patients with inherited PS deficiency who were admitted to the Institute of Hematology & Blood Diseases Hospital from June 2016 to February 2019 were analyzed: activity of protein C (PC) and antithrombin (AT) , PS activity were measured for phenotype diagnosis; high throughput sequencing (HTS) was used for screening of coagulation disease-related genes; Sanger sequencing was used to confirm candidate variants; Swiss-model was used for three-dimensional structure analysis. Results: The PS:C of 18 patients ranged from 12.5 to 48.2 U/dL. Among them, 16 cases developed deep vein thrombosis, including 2 cases each with mesenteric vein thrombosis and cerebral infarction, and 1 case each with pulmonary embolism and deep vein thrombosis during pregnancy. A total of 16 PROS1 gene mutations were detected, and 5 nonsense mutations (c.134_162del/p.Leu45*, c.847G>T/p.Glu283*, c.995_996delAT/p.Tyr332*, c.1359G> A/p.Trp453*, c.1474C>T/p.Gln492*) , 2 frameshift mutations (c.1460delG/p.Gla487Valfs*9 and c.1747_1750delAATC/p.Asn583Wfs*9) and 1 large fragment deletion (exon9 deletion) were reported for the first time. In addition, the PS:C of the deep vein thrombosis during pregnancy case was 55.2 U/dL carrying PROC gene c.565C>T/p.Arg189Trp mutation. Conclusion: The newly discovered gene mutations enriched the PROS1 gene mutation spectrum which associated with inherited PS deficiency.
Antithrombin III/genetics* ; Female ; Genetic Testing ; Humans ; Mutation ; Pregnancy ; Protein C/genetics* ; Protein S/genetics* ; Protein S Deficiency/genetics*

Objective: To explore the clinical characteristics and genotype of PROS1 gene related hereditary protein S deficiency (PSD) with the onset of pulmonary embolism in children. Methods: A family with pulmonary embolism was diagnosed as hereditary PSD in the Department of Pediatrics of Peking University First Hospital in November 2020, and the clinical data, including clinical manifestations, laboratory tests, imaging and genetic results, were collected for a retrospective research. The family members were also screened for protein S activity and PROS1 gene mutations. A literature search with "PROS1" "protein S deficiency" "homozygous" and "complex heterozygous" as key words was conducted at PubMed, China National Knowledge Infrastructure, and Wanfang Data Knowledge Service Platform (up to October 2021). Case reports of patients with PROS1 gene homozygous or complex heterozygous variants and related clinical features, protein S activity, and genotype were reviewed and analyzed. Results: The proband, a 14-year-old girl, was admitted to the hospital for a 9-day history of coughing and a 4-day history of chest pain in November 2020. After admission, laboratory tests showed that D-dimer was 8.38 mg/L (reference:<0.24 mg/L). An urgent CT pulmonary angiography confirmed bilateral pulmonary embolism and right lower pulmonary infarction, while an ultrasonography showed deep vein thrombosis in her left leg. Further examination revealed that protein S activity was less than 10%. The proband's second sister, a 12-year-old girl, was admitted to the hospital in December 2020. Her protein S activity was 8% and an ultrasonography showed deep vein thrombosis in her right leg. The protein S activity of the proband's father and mother were 36% and 26%, respectively. Trio-whole-exome sequencing detected compound heterozygous PROS1 gene variants (c.-168C>T and c.200A>C (p.E67A)) for the proband and her second sister, that were inherited from her father and mother, respectively. The proband's third sister's protein S activity was 28%; she and the proband's grandfather both carried c.200A>C (p.E67A) variants. The proband and her younger sister were treated with rivaroxaban and responded well during the 3-month follow-up. A total of 1 Chinese report in literature and 18 English literature were retrieved and 14 patients with protein S deficiency caused by homozygous or complex heterozygous variants of PROS1 gene were enrolled, including 8 male and 6 female patients. The ages ranged from 4 days to 35 years. Three patients experienced fulminant purpura or severe intracranial hemorrhage in early neonatal-period, while the remaining 11 patients developed venous thromboembolism in adolescence. Protein S activity was examined in 11 patients, and all showed less than 10% of activity. Missense variants was the most common type of gene variants. Conclusions: For children with pulmonary embolism, if there are no clear risk factors for thrombosis, hereditary protein S deficiency should be considered, and protein S activity should be examined before oral anticoagulant drugs. If protein S activity is less than 10%, protein S deficiency caused by homozygous or complex heterozygous variants should be considered.
Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Infant, Newborn ; Male ; Pedigree ; Protein S/genetics* ; Protein S Deficiency/genetics* ; Pulmonary Embolism/genetics* ; Retrospective Studies

OBJECTIVE: To test the anticoagulation functions, perform the genetic diagnosis and analyze the clinical characteristics in a family with combined heterozygous genetic variants of PROC and PROS1. METHODS: Peripheral blood was collected from all the family members. Hematological phenotypes and activity of anticoagulant factors were analyzed. Target genes were amplified by PCR from DNA isolated from peripheral blood, and then were analyzed by Sanger DNA sequencing. RESULTS: Many members in the family displayed the combined genetic variants in protein C and protein S, and six family members accompanied by deep venous thrombosis (DVT). The influences of genetic and secondary factors on the incidence of venous thrombosis in the family members were analyzed. The results showed that in this family, carriers of combined protein C and protein S gene defects had a higher incidence of VTE, but acquired factors still played a key role in the eventual thrombotic symptoms. CONCLUSION Venous thromboembolism (VTE) is a multifactorial disease, the combined genetic heterozygous mutations of protein C and S is an important genetic factor, and the clinical phenotype show a high heterogenicity, the secondary factors contribute to the VTE incidence.
Heterozygote ; Humans ; Mutation ; Protein C/genetics* ; Protein S/genetics* ; Risk Factors ; Venous Thromboembolism ; Venous Thrombosis/genetics*

Objective: To investigate the clinical characteristics and gene mutation, and analyze the association between genotype and phenotype of hereditary protein S deficiency in a Chinese pedigree. Methods: Hereditary protein S deficiency was diagnosed in January 2016 in our hospital. A total of 26 family members were surveyed in this study. Blood samples and clinical data were collected from them, and mutations were identified by Sanger sequencing. Pathogenicity of gene mutations was predicted by protein function prediction software including SIFT, PolyPhen_2, nsSNPAnalyzer and MutPred2. Swiss Model (https://swissmodel.expasy.org/) was used to perform homology modeling of the tertiary structure of the protein S wild-type and mutant-type, and observe the impact of gene mutation on the tertiary structure of the protein. Results: Four out of 26 family members of 4 generations were clinically diagnosed with hereditary protein S deficiency. The proband presented with recurrent pulmonary embolism and venous thromboembolism of the lower extremities, and her uncle and mother had a history of venous thromboembolism. Sequencing revealed a mutation in the c.200A>C gene in the second exon of the PROS1 gene of proband and part of her families (Ⅱ2, Ⅱ6, Ⅲ4, Ⅳ2). The prediction results of this gene mutation performed by SIFT, PolyPhen_2, nsSNPAnalyzer, MutPred2 were all harmful. The results of Swiss-Model homology modeling showed that the 67th amino acid was mutated from glutamic acid to alanine because of this gene mutation. Conclusion: A gene mutation cDNA (c. 200A>T) is identified in a Chinese pedigree with hereditary protein S deficiency. This gene mutation may reduce protein S activity, which may cause recurrent pulmonary embolism and venous thromboembolism of the patients.
Asians/genetics* ; Exons ; Female ; Humans ; Pedigree ; Protein S Deficiency ; Surveys and Questionnaires

Antiphospholipid antibodies may be produced in cases involving autoimmune diseases and can sometimes be caused by infections, such as Mycoplasma pneumoniae infection. However, antiphospholipid antibodies causing thrombosis associated with M. pneumoniae pneumonia in children have rarely been reported. We report a case of an 8-year-old boy with M. pneumoniae pneumonia with antiphospholipid antibodies, complicated by brachial artery thrombosis. He was found to have antiphospholipid antibodies and low protein S levels. The brachial artery thrombus was removed via thrombectomy. The titers of antiphospholipid antibodies turned normal within 5 months. This is a rare case of M. pneumoniae infection with brachial artery thrombosis associated with transient antiphospholipid antibodies.
Antibodies, Antiphospholipid ; Autoimmune Diseases ; Brachial Artery ; Child ; Humans ; Male ; Mycoplasma pneumoniae ; Mycoplasma ; Pneumonia ; Pneumonia, Mycoplasma ; Protein S ; Thrombectomy ; Thrombosis

BACKGROUND: Protein S deficiency is a common cause of thrombophilia. Free protein S has been suggested as one of the best screening tests for this deficiency. We evaluated an immunoturbidimetric free protein S reagent, INNOVANCE Free Protein S Antigen (Free PS Ag; Siemens Healthcare Diagnostics, Germany), using a CS-5100 coagulation analyzer (Sysmex, Japan). METHODS: The performance of INNOVANCE Free PS Ag was evaluated according to the CLSI guidelines. Precision, linearity, and verification of reference intervals were examined. The INNOVANCE Free PS Ag was also compared by the STA-Liatest Free Protein S immunoturbidimetric assay (Diagnostica Stago, France). RESULTS: The repeatability and within-laboratory imprecision of INNOVANCE Free PS Ag were 0.8% CV and 2.0% CV at the normal level, and 1.3% CV and 2.3% CV at the abnormally low level, respectively. This assay showed linearity from 4.0% to 151.9% (correlation coefficient r=1, P < 0.0001). Reference intervals for males and females were verified as acceptable. INNOVANCE Free PS Ag was comparable with STA-Liatest Free Protein S with a very high correlation (r=0.935, P < 0.0001). The results for the INNOVANCE antigen were higher. CONCLUSIONS: The INNOVANCE Free PS Ag on a Sysmex CS-5100 coagulation analyzer has excellent analytical performance and is comparable with the STA-Liatest Free Protein S assay.
Delivery of Health Care ; Female ; Humans ; Male ; Mass Screening ; Protein S Deficiency ; Protein S* ; Thrombophilia