| findkm

## Function

Find Km and Vmax for an enzyme reaction

## Description

Takes a file of enzymatic data and plots Michaelis Menten and Hanes Woolf plots of the data. From these it calculates the Michaelis Menten constant (Km) and the maximum velocity (Vmax) of the reaction.

## Usage

Here is a sample session with findkm

    % findkm -graph cps
    Find Km and Vmax for an enzyme reaction
    Enzyme kinetics data (application-specific) file: enztest.dat
    Output file [enztest.findkm]:

    Created findkm.ps

Go to the input files for this example
Go to the output files for this example

## Command line arguments

       Standard (Mandatory) qualifiers:
      [-infile]            infile     Enzyme kinetics data (application-specific)
                                      file
      [-outfile]           outfile    [*.findkm] Output file name
       -graphlb            xygraph    [$EMBOSS_GRAPHICS value, or x11] Graph type
                                      (ps, hpgl, hp7470, hp7580, meta, cps, x11,
                                      tekt, tek, none, data, xterm, png, gif)

       Additional (Optional) qualifiers: (none)
       Advanced (Unprompted) qualifiers:
       -[no]plot           boolean    [Y] S/V vs S

       Associated qualifiers:

       "-outfile" associated qualifiers
       -odirectory2        string     Output directory

       "-graphlb" associated qualifiers
       -gprompt            boolean    Graph prompting
       -gdesc              string     Graph description
       -gtitle             string     Graph title
       -gsubtitle          string     Graph subtitle
       -gxtitle            string     Graph x axis title
       -gytitle            string     Graph y axis title
       -goutfile           string     Output file for non interactive displays
       -gdirectory         string     Output directory

       General qualifiers:
       -auto               boolean    Turn off prompts
       -stdout             boolean    Write standard output
       -filter             boolean    Read standard input, write standard output
       -options            boolean    Prompt for standard and additional values
       -debug              boolean    Write debug output to program.dbg
       -verbose            boolean    Report some/full command line options
       -help               boolean    Report command line options. More
                                      information on associated and general
                                      qualifiers can be found with -help -verbose
       -warning            boolean    Report warnings
       -error              boolean    Report errors
       -fatal              boolean    Report fatal errors
       -die                boolean    Report dying program messages

Standard (Mandatory) qualifiers | Allowed values | Default
--- | --- | ---
[-infile] (Parameter 1) | Enzyme kinetics data (application-specific) file | Input file | Required
[-outfile] (Parameter 2) | Output file name | Output file | <*>.findkm
-graphlb | Graph type | EMBOSS has a list of known devices, including ps, hpgl, hp7470, hp7580, meta, cps, x11, tekt, tek, none, data, xterm, png, gif | EMBOSS_GRAPHICS value, or x11
Additional (Optional) qualifiers | Allowed values | Default
(none)
Advanced (Unprompted) qualifiers | Allowed values | Default
-[no]plot | S/V vs S | Boolean value Yes/No | Yes

## Input file format

The input file is a file of enzymatic data, [S] against V, Substrate concentration against reaction velocity.

### Input files for usage example

### File: enztest.dat

      0.10   2
      0.20   4
      0.50   9
      1.00  17
      2.00  29
      5.00  50
     10.00  67
     20.00  80
     50.00  91
    100.00  95

## Output file format

### Output files for usage example

### File: enztest.findkm

    ---Hanes Woolf Plot Calculations---
    Slope of best fit line is a = 0.01
    Coefficient in Eqn of line y = ma +b is b = 0.05
    Where line cuts x axis = (-0.20, 0)
    Where line cuts y axis = (0, 0.05)
    Limit-point of graph for plot = (103.00, 1.08)

    Vmax = 99.70, Km = 4.894611

### Graphics File: findkm.ps

## Data files

None.

## Notes

None.

## References

1. Voet & Voet (1993) 'Biochemistry'
2. Dawes 'Quantitative Problems in Biochemistry' 5th Edition.
3. Manuel G. Claros, Francisco M. Canovas 'Lines&Kinetics: a graphic tool to deal with linear regressions and enzyme kinetics.' EMBnet.news vol 5.1 http://www.uk.embnet.org/embnet.news/vol5_1/kinetics.html
4. Cornish-Bowden (1996) 'Fundamentals of Enzyme kinetics' Portland Press, London.

## Warnings

None.

## Diagnostic Error Messages

None.

## Exit status

It exits with a status of 0.

## Known bugs

None.

## See also

Program name | Description
--- | ---

## Author(s)

Sinead O'Leary (current e-mail address unknown)
while she was at:
HGMP-RC, Genome Campus, Hinxton, Cambridge CB10 1SB, UK

This application was modified by David Martin (dmartin © rfcgr.mrc.ac.uk)

## History

Completed November 1999

Modified May 2000

## Target users

This program is intended to be used by everyone and everything, from naive users to embedded scripts.

## Comments

None