Molecular modelers often face challenges in efficiently analyzing and filtering molecular structures. The Segment attribute space, part of SAMSON’s Node Specification Language (NSL), provides a powerful way to describe and interact with segment nodes, helping streamline molecular workflows.
What Are Segment Attributes?
Segment attributes allow researchers to define and query properties specific to molecular segments. These attributes belong to the segment attribute space (short name: s) and include inherited attributes from the node and structuralGroup attribute spaces, as well as attributes unique to segments.
Key Attributes and Use Cases
Here are some practical examples of segment attributes and how they can be leveraged in molecular modeling:
1. Filtering by Number of Residues
The numberOfResidues attribute (short name: s.nr) lets you specify segments based on residue counts:
s.nr > 100: Matches segments with more than 100 residues.s.nr 100:120: Matches segments with residue counts between 100 and 120.
This is particularly useful when analyzing large protein structures and focusing on regions of interest.
2. Determining Molecular Composition
Simplify your molecular analysis by using attributes like numberOfCarbons (s.nC) or numberOfHydrogens (s.nH) to query specific elements within segment nodes:
s.nC < 10: Matches segments with fewer than 10 carbons.s.nH 10:20: Matches segments with hydrogen counts between 10 and 20.
This helps identify specific molecular characteristics within complex systems.
3. Visibility and Selection Control
Attributes such as visible (s.v) and selected make it easier to filter and manage segment nodes in your workspace:
s.v: Matches visible segments.not s.v: Matches segments that are not currently visible.s.selected: Matches segments that have been selected in the model.
These controls enhance your ability to focus on specific parts of your molecular models during exploration and analysis.
4. Analyzing Charge Properties
You can use the formalCharge (s.fc) and partialCharge (s.pc) attributes to analyze charges:
s.fc > 1: Matches segments with a formal charge greater than 1.s.pc 1.5:2.0: Matches segments with a partial charge between 1.5 and 2.0.
This facilitates the study of electrostatic properties in biomolecular systems.
Practical Example for Modelers
Suppose you’re analyzing a protein structure and need to identify segments with over 130 residues that also contain fewer than 20 carbon atoms. By combining attributes, you can easily run the following query:
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s.nr > 130 and s.nC < 20 |
This reduces the time spent manually searching for specific segments and ensures a more efficient workflow.
Conclusion
Segment attributes in SAMSON unlock significant potential for molecular modelers, offering an intuitive yet robust way to query, analyze, and filter molecular data. To explore the full range of segment attributes and their practical applications, visit the official SAMSON documentation page.
SAMSON and all SAMSON Extensions are free for non-commercial use. Visit https://www.samson-connect.net to get started today.