Role of vitamin B12 in methyl transfer for methane biosynthesis by Methanosarcina barkeri

Science ◽  
1982 ◽  
Vol 216 (4543) ◽  
pp. 303-305 ◽  
Author(s):  
J. Wood ◽  
I Moura ◽  
J. Moura ◽  
M. Santos ◽  
A. Xavier ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Methanosarcina Barkeri ◽  
Methyl Transfer

THE ROLE OF VITAMIN B12 IN METHYL TRANSFER TO HOMOCYSTEINE*

2006 ◽  
Vol 112 (2) ◽  
pp. 756-773 ◽  
Author(s):  
J. M. Buchanan ◽  
H. L. Elford ◽  
R. E. Loughlin ◽  
B. M. McDougall ◽  
S. Rosenthal
Keyword(s):  
Vitamin B12 ◽  
Methyl Transfer

Cubilin, the Intrinsic Factor-Vitamin B12 Receptor in Development and Disease

2020 ◽  
Vol 27 (19) ◽  
pp. 3123-3150 ◽  
Author(s):  
Renata Kozyraki ◽  
Olivier Cases
Keyword(s):  
Vitamin B12 ◽  
Cancer Progression ◽  
Intrinsic Factor ◽  
Basic Research ◽  
Toxic Substances ◽  
Human Pathology ◽  
Peripheral Membrane Protein ◽  
Epidermal Growth ◽  
Fgf8 Signaling

Gp280/Intrinsic factor-vitamin B12 receptor/Cubilin (CUBN) is a large endocytic receptor serving multiple functions in vitamin B12 homeostasis, renal reabsorption of protein or toxic substances including albumin, vitamin D-binding protein or cadmium. Cubilin is a peripheral membrane protein consisting of 8 Epidermal Growth Factor (EGF)-like repeats and 27 CUB (defined as Complement C1r/C1s, Uegf, BMP1) domains. This structurally unique protein interacts with at least two molecular partners, Amnionless (AMN) and Lrp2/Megalin. AMN is involved in appropriate plasma membrane transport of Cubilin whereas Lrp2 is essential for efficient internalization of Cubilin and its ligands. Observations gleaned from animal models with Cubn deficiency or human diseases demonstrate the importance of this protein. In this review addressed to basic research and medical scientists, we summarize currently available data on Cubilin and its implication in renal and intestinal biology. We also discuss the role of Cubilin as a modulator of Fgf8 signaling during embryonic development and propose that the Cubilin-Fgf8 interaction may be relevant in human pathology, including in cancer progression, heart or neural tube defects. We finally provide experimental elements suggesting that some aspects of Cubilin physiology might be relevant in drug design.

scholarly journals Current Nanocarrier Strategies Improve Vitamin B12 Pharmacokinetics, Ameliorate Patients’ Lives, and Reduce Costs

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 743
Author(s):  
Marco Fidaleo ◽  
Stefano Tacconi ◽  
Carolina Sbarigia ◽  
Daniele Passeri ◽  
Marco Rossi ◽  
...  
Keyword(s):  
Side Effects ◽  
Vitamin B12 ◽  
Memory Performance ◽  
Oral Route ◽  
High Dose ◽  
Human Beings ◽  
Inborn Errors ◽  
Essential Nutrient

Vitamin B12 (VitB12) is a naturally occurring compound produced by microorganisms and an essential nutrient for humans. Several papers highlight the role of VitB12 deficiency in bone and heart health, depression, memory performance, fertility, embryo development, and cancer, while VitB12 treatment is crucial for survival in inborn errors of VitB12 metabolism. VitB12 is administrated through intramuscular injection, thus impacting the patients’ lifestyle, although it is known that oral administration may meet the specific requirement even in the case of malabsorption. Furthermore, the high-dose injection of VitB12 does not ensure a constant dosage, while the oral route allows only 1.2% of the vitamin to be absorbed in human beings. Nanocarriers are promising nanotechnology that can enable therapies to be improved, reducing side effects. Today, nanocarrier strategies applied at VitB12 delivery are at the initial phase and aim to simplify administration, reduce costs, improve pharmacokinetics, and ameliorate the quality of patients’ lives. The safety of nanotechnologies is still under investigation and few treatments involving nanocarriers have been approved, so far. Here, we highlight the role of VitB12 in human metabolism and diseases, and the issues linked to its molecule properties, and discuss how nanocarriers can improve the therapy and supplementation of the vitamin and reduce possible side effects and limits.

scholarly journals Role of S-Adenosylmethionine in Vitamin B12-dependent Methionine Synthesis

1966 ◽  
Vol 241 (15) ◽  
pp. 3641-3642
Author(s):  
Robert T. Taylor ◽  
Herbert Weissbach
Keyword(s):  
Vitamin B12 ◽  
Methionine Synthesis

A Possible Role of Iodinated Casein in Intestinal Assimilation of Vitamin B12.

1954 ◽  
Vol 86 (1) ◽  
pp. 8-11 ◽  
Author(s):  
A. K. Kano ◽  
J. A. Anderson ◽  
D. F. Hougham ◽  
L. W. Charkey
Keyword(s):  
Vitamin B12

scholarly journals The Role of Vitamin B12 in Methionine Biosynthesis in Avian Liver

1964 ◽  
Vol 239 (8) ◽  
pp. 2545-2552
Author(s):  
Herbert Dickerman ◽  
Betty G. Redfield ◽  
J.G. Bieri ◽  
Herbert Weissbach
Keyword(s):  
Vitamin B12 ◽  
Methionine Biosynthesis

scholarly journals The folate-binding module ofThermus thermophiluscobalamin-dependent methionine synthase displays a distinct variation of the classical TIM barrel: a TIM barrel with a `twist'

2018 ◽  
Vol 74 (1) ◽  
pp. 41-51
Author(s):  
Kazuhiro Yamada ◽  
Markos Koutmos
Keyword(s):  
Tertiary Amine ◽  
Thermus Thermophilus ◽  
Methionine Synthase ◽  
Structural Studies ◽  
Binding Domains ◽  
Methyl Transfer ◽  
Structural Differences ◽  
Tim Barrel ◽  
Eukaryotic Organisms

Methyl transfer between methyltetrahydrofolate and corrinoid molecules is a key reaction in biology that is catalyzed by a number of enzymes in many prokaryotic and eukaryotic organisms. One classic example of such an enzyme is cobalamin-dependent methionine synthase (MS). MS is a large modular protein that utilizes an SN2-type mechanism to catalyze the chemically challenging methyl transfer from the tertiary amine (N5) of methyltetrahydrofolate to homocysteine in order to form methionine. Despite over half a century of study, many questions remain about how folate-dependent methyltransferases, and MS in particular, function. Here, the structure of the folate-binding (Fol) domain of MS fromThermus thermophilusis reported in the presence and absence of methyltetrahydrofolate. It is found that the methyltetrahydrofolate-binding environment is similar to those of previously described methyltransferases, highlighting the conserved role of this domain in binding, and perhaps activating, the methyltetrahydrofolate substrate. These structural studies further reveal a new distinct and uncharacterized topology in the C-terminal region of MS Fol domains. Furthermore, it is found that in contrast to the canonical TIM-barrel β8α8fold found in all other folate-binding domains, MS Fol domains exhibit a unique β8α7fold. It is posited that these structural differences are important for MS function.

Sign in / Sign up

Export Citation Format

Share Document