how to find the bound form of an enzyme structure? For my undergraduate research I'm looking for a database that gives the bound form of a particular protein structure. Is there any database that provide us with such data? So far I've found following proteins related to my work 


Ascorbate peroxidase (APX)
Beta-glucosidase
Calcineurin b-like protein-interacting protein kinase.


I've searched in PDB and UNIPROT.
Tried looking for an explicit database? i.e.


ComSin: database of protein structures in bound (complex) and unbound (single) states in relation to their intrinsic disorder: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2808974/ or
LigASite: a database of biologically relevant binding sites in proteins with known apo-structures https://www.ncbi.nlm.nih.gov/pubmed/17933762


Else the PDB itself has a very powerful advanced search that should allow you to do this: http://www.rcsb.org/pdb/search/advSearch.do