Dld (software)

Dld was a library package for the C programming language that performs dynamic link editing. Programs that use dld can add or remove compiled object code from a process anytime during its execution. Loading modules, searching libraries, resolving external references, and allocating storage for global and static data structures are all performed at run time.

Dld supported various Unix platforms, having originally been developed for the VAX, Sun-3 and SPARCstation architectures. Its authors contrast its functionality with the dynamic linking that was at the time of its construction available in operating systems such as SunOS 4, System V.4, HP-UX and VMS: all of these operating systems had shared libraries, but did not allow programs to load additional libraries after startup. Dld offered this functionality without requiring changes to the OS or toolchain.

Dld was a GNU package, but has been withdrawn because its functionality is available (through the dlopen API) in modern Unix-like operating systems.

DLD

DLD can refer to:

Dihydrolipoamide dehydrogenase

Dihydrolipoamide dehydrogenase (DLD), also known as dihydrolipoyl dehydrogenase, mitochondrial, is an enzyme that in humans is encoded by the DLD gene. DLD is a flavoprotein enzyme that oxidizes dihydrolipoamide to lipoamide.

Dihydrolipoamide dehydrogenase (DLD) is a mitochondrial enzyme that plays a vital role in energy metabolism in eukaryotes. This enzyme is required for the complete reaction of at least five different multi-enzyme complexes. Additionally, DLD is a flavoenzyme oxidoreductase that contains a reactive disulfide bridge and a FAD cofactor that are directly involved in catalysis. The enzyme associates into tightly bound homodimers required for its enzymatic activity.

Lipoamide

Lipoamide

Dihydrolipoamide

Dihydrolipoamide

Structure

The protein encoded by the DLD gene comes together with another protein to form a dimer in the central metabolic pathway. Several amino acids within the catalytic pocket have been identified as important to DLD function, including R281 and N473. Although the overall fold of the human enzyme is similar to that of yeast, the human structure is different in that it has two loops that extend from the general protein structure and into the FAD binding sites. When bound the NAD+ molecule, required for catalysis, is not close to the FAD moiety. However, when NADH is bound instead, it is stacked directly op top of the FAD central structure. The current hE3 structures show directly that the disease-causing mutations occur at three locations in the human enzyme: the dimer interface, the active site, and the FAD and NAD(+)-binding sites.