Covalently linked phosphate monoesters on alpha-polyglucans reduce substrate affinity of branching enzymes
Bibliographic record
Abstract
Starch and glycogen are α-polyglucans which represent important sources of long- and short-term cellular carbohydrate storage synthesized in living cells. Both polyglucans contain variable, but significant, levels of covalently bound phosphate monoesters whose biological role is likely connected to the regulation of turnover of these storage polymers by promoting water solubility. The amount of α-glucan-bound phosphate found in plant starch appears to be closely related to the average chain length of α-1,4-glucans, and inversely related to the frequency of α-1,6-branch linkages. The enzymes responsible for adding branches to linear α-1,4-glucan chains in starch and glycogen are 1,4-α-glucan: 1,4-α-glucan 6-glucosyl transferases (branching enzymes). In this study, glucan bound phosphate was shown to reduce the affinity of branching enzymes for α-glucan substrates. Plant starch branching enzymes and glycogen branching enzymes from various prokaryotic and eukaryotic sources showed reduced substrate affinities in native gels as the α-glucan phosphate content was increased. The substrate affinities of all branching enzymes tested showed an inverse linear relationship with α-glucan phosphate content. The possible biological significance of this phenomenon is discussed in relation to known models of starch structure in plants and specific glycogen storage diseases in mammals.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".