Asset Details
Do you wish to reserve the book?
Dietary factors potentially impacting thiaminase I-mediated thiamine deficiency
Hey, we have placed the reservation for you!
By the way, why not check out events that you can attend while you pick your title.
Oops! Something went wrong.
Looks like we were not able to place the reservation. Kindly try again later.
Are you sure you want to remove the book from the shelf?
Dietary factors potentially impacting thiaminase I-mediated thiamine deficiency
Do you wish to request the book?
Dietary factors potentially impacting thiaminase I-mediated thiamine deficiency
Please be aware that the book you have requested cannot be checked out. If you would like to checkout this book, you can reserve another copy
We have requested the book for you!
Your request is successful and it will be processed during the Library working hours. Please check the status of your request in My Requests.
Oops! Something went wrong.
Looks like we were not able to place your request. Kindly try again later.
Journal Article
Dietary factors potentially impacting thiaminase I-mediated thiamine deficiency
2023
Overview
Fish population declines from thiamine (vitamin B1) deficiency have been widespread in ecologically and economically valuable organisms, ranging from the Great Lakes to the Baltic Sea and, most recently, the California coast. Thiamine deficiencies in predatory fishes are often attributed to a diet of prey fishes with high levels of thiamine-degrading (e.g., thiaminase) enzymes, such as alewives, rainbow smelt, and anchovies. Since their discovery, thiaminase I enzymes have been recognized for breaking down thiamine into its pyrimidine and thiazole moieties using various nucleophilic co-substrates to afford cleavage, but these studies have not thoroughly considered other factors that could modify enzyme activity. We found the thiaminase I enzyme from
Clostridium botulinum
efficiently degrades thiamine in the presence of pyridoxine (vitamin B6) as a co-substrate but has relatively limited activity in the presence of nicotinic acid (vitamin B3). Using fluorescence measurements, thiamine degradation in an over-the-counter complete multivitamin formulation was inhibited, and a B-complex formulation required co-substrate supplementation for maximal thiamine depletion. These studies prompted the evaluation of specific constituents contributing to thiaminase I inhibition by both chromatography and fluorescence assays: Cu
2+
potently and irreversibly inhibited thiamine degradation; ascorbic acid was a strong but reversible inhibitor; Fe
2+
, Mn
2+
and Fe
3+
modulated thiamine degradation to a lesser degree. The enhancement by pyridoxine and inhibition by Cu
2+
extended to thiaminase-mediated degradation from
Burkholderia thailandensis
,
Paenibacillus thiaminolyticus
, and
Paenibacillus apiarius
in tryptic soy broth supernatants. These co-substrate limitations and the common presence of inhibitory dietary factors complement recent studies reporting that the intended function of thiaminase enzymes is to recycle thiamine breakdown products for thiamine synthesis, not thiamine degradation.
Publisher
Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
Subject
